Aimathic
Login | English | Deutsch

Grade 6 math worksheets

Build your own math worksheets from 35,000+ problems for grades 3 to 12, from fractions to AP Calculus. Every problem comes with step-by-step solutions.

Compare and order rational numbers

Learning goals

  • Compares the given quantities or objects using the relevant attribute or value.
  • Uses appropriate comparison symbols or language.
  • Justifies comparisons using numerical, measurement, or structural evidence.

Click problems to add them to your worksheet.

Compare and order rational numbers 1
Five cities recorded these low temperatures on a winter day: \(3\,^\circ\text{F}\), \(-7\,^\circ\text{F}\), \(0\,^\circ\text{F}\), \(-2\,^\circ\text{F}\), and \(-12\,^\circ\text{F}\). Order the temperatures from coldest to warmest using \(<\).

Hints

- Picture the temperatures on a thermometer. - Which temperature is farthest below zero? - Where does zero belong relative to the negative temperatures?

Solution

1. Among the negative temperatures, the value farther left on a number line is colder: \(-12<-7<-2\). 2. Zero is greater than every negative number, and \(3\) is greater than zero. 3. Therefore, \(-12<-7<-2<0<3\).

Answer

\(-12\,^\circ\text{F}<-7\,^\circ\text{F}<-2\,^\circ\text{F}<0\,^\circ\text{F}<3\,^\circ\text{F}\)
Compare and order rational numbers 2
Which number is less, \(-450\) or \(-405\)? Explain using their positions on a horizontal number line.

Hints

- Locate zero and determine which direction contains lesser numbers. - Compare how far each number is from zero. - The number farther to the left is less.

Solution

1. On a number line, the number farther to the left is less. 2. Because \(-450\) lies farther left than \(-405\), \(-450<-405\).

Answer

\(-450\) is less because it lies farther to the left on the number line.
Compare and order rational numbers 3
Fill in \(<\), \(>\), or \(=\): \(-\frac{3}{8}\quad\square\quad-\frac{5}{8}\). Explain your choice.

Hints

- Both fractions are divided into equally sized parts. - Which negative number lies closer to zero? - The number farther right is greater.

Solution

1. The fractions have the same denominator, so compare the eighths. 2. \(-3\) eighths is farther right on the number line than \(-5\) eighths. 3. Therefore, \(-\frac{3}{8}>-\frac{5}{8}\).

Answer

\(>\), because \(-\frac{3}{8}\) lies to the right of \(-\frac{5}{8}\) on the number line.
Compare and order rational numbers 4
Which is greater, \(0.407\) or \(0.47\)? Explain without rounding.

Hints

- Compare tenths first, then hundredths, then thousandths if needed. - Adding a zero at the end of a decimal does not change its value. - Do not decide by counting digits alone.

Solution

1. Write \(0.47\) as \(0.470\) so the decimal places align. 2. Compare thousandths: \(407<470\). 3. Therefore, \(0.47>0.407\).

Answer

\(0.47\), because \(0.470>0.407\) when their decimal places are aligned.
Compare and order rational numbers 5
A trail is \(\frac{3}{4}\) mile long. Another trail is \(0.7\) mile long. Which is longer? Explain.

Hints

- Think of three quarters of one unit. - Express both lengths in the same form. - Compare the two lengths after using one form.

Solution

1. \(\frac{3}{4}=0.75\) mile. 2. Compare \(0.75>0.70\). 3. The first trail is longer.

Answer

The \(\frac{3}{4}\)-mile trail, because \(\frac{3}{4}=0.75>0.70=0.7\).
Compare and order rational numbers 6
Which fraction is greatest? a) \(\frac{2}{3}\) b) \(\frac{3}{5}\) c) \(\frac{4}{7}\) d) \(\frac{5}{8}\)

Hints

- Convert each fraction to a decimal. - Compare the decimal values digit by digit. - A rounded decimal can be used as long as it clearly separates the values.

Solution

1. Write each fraction as a decimal: \(\frac{2}{3}\approx0.667\), \(\frac{3}{5}=0.6\), \(\frac{4}{7}\approx0.571\), and \(\frac{5}{8}=0.625\). 2. Since \(0.667\) is the greatest decimal, \(\frac{2}{3}\) is the greatest fraction.

Answer

a) \(\frac{2}{3}\)
Compare and order rational numbers 7
Compare the two quotients. Which is greater? Justify your answer by writing both in a common form. \(A=13\div5\) \(B=21\div8\)

Hints

- Put both quotients in the same representation before comparing. - If you use decimals, align the place values. - When the whole-number and tenths digits match, compare the next place.

Solution

1. Convert the quotients to decimals: \(13\div5=2.6\) and \(21\div8=2.625\). 2. Write \(2.6\) as \(2.600\) so the place values align. 3. Since \(2.625>2.600\), \(B>A\).

Answer

\(B\) is greater because \(2.625>2.600\).
Compare and order rational numbers 8
Compare the two part-to-whole fractions. Which fraction is greater? a) \(450\,\text{g}\) out of \(1.5\,\text{kg}\) b) \(12\,\text{min}\) out of \(0.5\,\text{hr}\)

Hints

- Convert each part and whole to matching units. - Write each comparison as \(\frac{\text{part}}{\text{whole}}\). - Use equivalent fractions with a common denominator to compare.

Solution

1. For a), convert \(1.5\,\text{kg}\) to \(1500\,\text{g}\). The fraction is \(\frac{450}{1500}=\frac{3}{10}\). 2. For b), convert \(0.5\,\text{hr}\) to \(30\,\text{min}\). The fraction is \(\frac{12}{30}=\frac{2}{5}=\frac{4}{10}\). 3. Since \(\frac{4}{10}>\frac{3}{10}\), the fraction in b) is greater.

Answer

The fraction in b), \(12\,\text{min}\) out of \(0.5\,\text{hr}\), is greater.
Compare and order rational numbers 9
Find all fractions of the form \(\frac{k}{12}\), where \(k\) is a natural number, that are greater than \(\frac{1}{2}\) and less than \(\frac{5}{6}\). Write each result in simplest form.

Hints

- Rewrite both boundary fractions with denominator \(12\). - Identify the integer numerators between the two boundary numerators. - Simplify every resulting fraction.

Solution

1. Rewrite the bounds with denominator \(12\): \(\frac{1}{2}=\frac{6}{12}\) and \(\frac{5}{6}=\frac{10}{12}\). 2. The numerators strictly between \(6\) and \(10\) are \(7\), \(8\), and \(9\). 3. The fractions are \(\frac{7}{12}\), \(\frac{8}{12}\), and \(\frac{9}{12}\). 4. Simplify: \(\frac{7}{12}\), \(\frac{2}{3}\), and \(\frac{3}{4}\).

Answer

\(\frac{7}{12},\frac{2}{3},\frac{3}{4}\)
Compare and order rational numbers 10
Order the rational numbers from least to greatest: \(-\frac{3}{4}\), \(-\frac{5}{8}\), \(-\frac{11}{16}\)

Hints

- Rewrite the fractions with a common denominator. - For negative numbers, the value farther left on the number line is smaller. - Compare the equivalent numerators carefully.

Solution

1. Use a common denominator of \(16\): \(-\frac{3}{4} = -\frac{12}{16}\), \(-\frac{5}{8} = -\frac{10}{16}\), and \(-\frac{11}{16}\) is unchanged. 2. Compare the numerators: \(-12 < -11 < -10\). 3. Therefore, \(-\frac{3}{4} < -\frac{11}{16} < -\frac{5}{8}\).

Answer

\(-\frac{3}{4} < -\frac{11}{16} < -\frac{5}{8}\)
Compare and order rational numbers 11
Insert \(<\), \(>\), or \(=\) in each blank. a) \(-\frac{3}{5} \;\square\; -0.5\) b) \(1\frac{1}{8} \;\square\; 1.125\) c) \(-0.33 \;\square\; -\frac{1}{3}\)

Hints

- Convert each pair to the same form. - Of two negative numbers, the one closer to zero is greater. - A repeating decimal continues beyond the shown digits.

Solution

1. For a), \(-\frac{3}{5} = -0.6\). Since \(-0.6 < -0.5\), the correct symbol is \(<\). 2. For b), \(1\frac{1}{8} = 1 + 0.125 = 1.125\), so the values are equal. 3. For c), \(-\frac{1}{3} = -0.3333\ldots\). Since \(-0.3300\ldots > -0.3333\ldots\), \(-0.33 > -\frac{1}{3}\).

Answer

a) \(-\frac{3}{5} < -0.5\) b) \(1\frac{1}{8} = 1.125\) c) \(-0.33 > -\frac{1}{3}\)
Compare and order rational numbers 12
Which rational number is greater: \(-4.6\) or \(-4\frac{2}{3}\)? Explain using their positions on the number line.

Hints

- Convert the mixed number to a decimal. - For two negative values, the one closer to zero is greater. - Think about which point lies farther right on the number line.

Solution

1. Convert the mixed number: \(-4\frac{2}{3} = -4.6666\ldots\). 2. Compare the absolute values: \(4.6 < 4.6666\ldots\). 3. Of two negative numbers, the one with the smaller absolute value lies farther right and is greater. 4. Therefore, \(-4.6 > -4\frac{2}{3}\).

Answer

\(-4.6\) is greater than \(-4\frac{2}{3}\).
Compare and order rational numbers 13
Insert \(<\), \(>\), or \(=\) in each blank. a) \(0.708 \;\square\; 0.71\) b) \(-0.52 \;\square\; -0.502\) c) \(\frac{3}{8} \;\square\; 0.375\) d) \(-\frac{2}{3} \;\square\; -0.6\)

Hints

- Add trailing zeros to align decimal places. - For negative numbers, the value farther left is smaller. - Convert fractions to decimals when useful. - A negative number with greater absolute value is smaller.

Solution

1. For a), compare \(0.708\) and \(0.710\). Since \(708 < 710\) thousandths, \(0.708 < 0.71\). 2. For b), \(-0.520\) lies to the left of \(-0.502\), so \(-0.52 < -0.502\). 3. For c), \(\frac{3}{8} = 3 \div 8 = 0.375\), so the values are equal. 4. For d), \(-\frac{2}{3} = -0.6666\ldots\), which is less than \(-0.6000\ldots\). Therefore, \(-\frac{2}{3} < -0.6\).

Answer

a) \(0.708 < 0.71\) b) \(-0.52 < -0.502\) c) \(\frac{3}{8} = 0.375\) d) \(-\frac{2}{3} < -0.6\)
Compare and order rational numbers 14
Convert the values to percents and order each set from least to greatest using \(<\). a) \(\frac{3}{8}\); \(0.37\); \(38\%\) b) \(0.6\); \(\frac{5}{8}\); \(61\%\)

Hints

- Write all three values in each set in the same form, such as percents. - Divide the numerator by the denominator to write a fraction as a decimal. - Multiply a decimal by \(100\) to write it as a percent.

Solution

1. For a), \(\frac{3}{8} = 0.375 = 37.5\%\), \(0.37 = 37\%\), and \(38\%\) is already a percent. Since \(37\% < 37.5\% < 38\%\), the order is \(0.37 < \frac{3}{8} < 38\%\). 2. For b), \(0.6 = 60\%\), \(\frac{5}{8} = 0.625 = 62.5\%\), and \(61\%\) is already a percent. Since \(60\% < 61\% < 62.5\%\), the order is \(0.6 < 61\% < \frac{5}{8}\).

Answer

a) \(0.37 < \frac{3}{8} < 38\%\) b) \(0.6 < 61\% < \frac{5}{8}\)
Compare and order rational numbers 15
Order the following numbers from least to greatest: \(0.3\); \(\frac{1}{4}\); \(28\%\); \(\frac{7}{20}\)

Hints

- Would it help to write all the numbers in the same form? - Which form—fractions, decimals, or percents—is easiest for you to compare?

Solution

1. Write each value as a percent: \(0.3 = 30\%\) \(\frac{1}{4} = \frac{25}{100} = 25\%\) \(28\%\) is already a percent. \(\frac{7}{20} = \frac{35}{100} = 35\%\) 2. Compare the percents: \(25\% < 28\% < 30\% < 35\%\). 3. Replace the percents with the original values: \(\frac{1}{4} < 28\% < 0.3 < \frac{7}{20}\).

Answer

\(\frac{1}{4} < 28\% < 0.3 < \frac{7}{20}\)
Compare and order rational numbers 16
Write each value as a percent. Then order the original values from least to greatest using \(<\) or \(=\). \(0.12\); \(\frac{1}{8}\); \(13\%\); \(\frac{3}{25}\)

Hints

- How many hundredths is \(0.12\)? - Write each fraction with denominator \(100\), or divide to find its decimal value. - Are any two values equal?

Solution

1. Convert each value to a percent: \(0.12 = 12\%\) \(\frac{1}{8} = 0.125 = 12.5\%\) \(13\%\) is already a percent. \(\frac{3}{25} = \frac{12}{100} = 12\%\) 2. Compare the percents: \(12\% = 12\% < 12.5\% < 13\%\). 3. The original values are ordered as \(0.12 = \frac{3}{25} < \frac{1}{8} < 13\%\).

Answer

Percents: \(12\%\); \(12.5\%\); \(13\%\); \(12\%\) Order: \(0.12 = \frac{3}{25} < \frac{1}{8} < 13\%\)
Compare and order rational numbers 17
Determine which values are greater than \(5\%\). Write each value as a percent rounded to the nearest tenth of a percent. a) \(\frac{1}{22}\) b) \(0.049\) c) \(\frac{3}{55}\) d) \(0.051\)

Hints

- Express every value in the requested percent form before comparing with \(5\%\). - For repeating values, keep enough digits to round to the nearest tenth of a percent. - Check which rounded percents lie on the greater-than side of \(5\%\).

Solution

1. For a), \(\frac{1}{22} = 0.04545\ldots = 4.545\ldots\% \approx 4.5\%\). This is less than \(5\%\). 2. For b), \(0.049 = 4.9\%\). This is less than \(5\%\). 3. For c), \(\frac{3}{55} = 0.05454\ldots = 5.454\ldots\% \approx 5.5\%\). This is greater than \(5\%\). 4. For d), \(0.051 = 5.1\%\). This is greater than \(5\%\).

Answer

a) \(\frac{1}{22} \approx 4.5\%\) b) \(0.049 = 4.9\%\) c) \(\frac{3}{55} \approx 5.5\%\) d) \(0.051 = 5.1\%\) The values greater than \(5\%\) are c) and d).
Compare and order rational numbers 18
Compare each pair. Write \(<\), \(>\), or \(=\) in the blank, and justify each answer with a short calculation. a) One out of every twenty \(\square\) \(4\%\) b) \(15\) out of \(1000\) \(\square\) \(1.5\%\) c) Three out of four \(\square\) \(70\%\) d) \(0.025\) \(\square\) one out of every forty

Hints

- Express both values in each pair in a common form. - A phrase such as “one out of every twenty” names a fraction. - You can use decimals or percents to check each comparison.

Solution

1. \(\frac{1}{20}=5\%>4\%\), so a) is \(>\). 2. \(\frac{15}{1000}=1.5\%\), so b) is \(=\). 3. \(\frac{3}{4}=75\%>70\%\), so c) is \(>\). 4. \(\frac{1}{40}=0.025\), so d) is \(=\).

Answer

a) \(>\), since \(\frac{1}{20}=5\%>4\%\). b) \(=\), since \(\frac{15}{1000}=1.5\%\). c) \(>\), since \(\frac{3}{4}=75\%>70\%\). d) \(=\), since \(\frac{1}{40}=0.025\).
Compare and order rational numbers 19
Write each value as a percent, then order the original values from least to greatest: \(0.5\); \(\frac{1}{4}\); \(0.2\); \(\frac{3}{10}\); \(15\%\)

Hints

- Can you write every value in hundredths? - How does the decimal point move when you write a decimal as a percent? - Put all values in the same form before comparing them.

Solution

1. Convert each value to a percent: \(0.5 = 50\%\), \(\frac{1}{4} = 25\%\), \(0.2 = 20\%\), and \(\frac{3}{10} = 30\%\). 2. Compare the percent values: \(15\% < 20\% < 25\% < 30\% < 50\%\). 3. The original values are ordered as \(15\% < 0.2 < \frac{1}{4} < \frac{3}{10} < 0.5\).

Answer

\(15\% < 0.2 < \frac{1}{4} < \frac{3}{10} < 0.5\)
Compare and order rational numbers 20
First write each fraction as a percent. Then order the percent values from least to greatest using \(<\). a) \(\frac{3}{4}\) b) \(\frac{13}{50}\) c) \(\frac{7}{25}\) d) \(\frac{120}{1000}\)

Hints

- How can you simplify or scale each fraction to get denominator \(100\)? - What does “percent” mean? - Once the denominator is \(100\), the numerator gives the percent.

Solution

1. Convert each fraction: \(\frac{3}{4} = \frac{75}{100} = 75\%\), \(\frac{13}{50} = \frac{26}{100} = 26\%\), \(\frac{7}{25} = \frac{28}{100} = 28\%\), and \(\frac{120}{1000} = \frac{12}{100} = 12\%\). 2. Compare the percents: \(12\% < 26\% < 28\% < 75\%\).

Answer

a) \(75\%\) b) \(26\%\) c) \(28\%\) d) \(12\%\) Order: \(12\% < 26\% < 28\% < 75\%\)
Compare and order rational numbers 21
Compare \(0.4\) and \(\frac{9}{25}\). Which value is greater? Justify your answer by writing both values as percents.

Hints

- What percent is \(0.4\)? - What can you multiply \(25\) by to get \(100\)? - Once both values are percents, compare them.

Solution

1. Convert \(0.4\) to a percent: \(0.4 = \frac{40}{100} = 40\%\). 2. Write \(\frac{9}{25}\) with denominator \(100\): \(\frac{9}{25} = \frac{36}{100} = 36\%\). 3. Since \(40\% > 36\%\), \(0.4\) is greater than \(\frac{9}{25}\).

Answer

\(0.4\) is greater because \(40\% > 36\%\).
Compare and order rational numbers 22
Order these numbers from least to greatest using \(<\): \(0.45\), \(\frac{2}{5}\), \(0.405\), \(\frac{11}{25}\)

Hints

- Convert the fractions to decimals. - Add trailing zeros mentally so each decimal has the same number of places. - Compare tenths, then hundredths, then thousandths.

Solution

1. Convert the fractions to decimals: \(\frac{2}{5}=0.4\) and \(\frac{11}{25}=\frac{44}{100}=0.44\). 2. Compare the decimals: \(0.4<0.405<0.44<0.45\). 3. Write the original values in that order: \(\frac{2}{5}<0.405<\frac{11}{25}<0.45\).

Answer

\(\frac{2}{5}<0.405<\frac{11}{25}<0.45\)
Compare and order rational numbers 23
Insert \(<\), \(>\), or \(=\) in each blank. a) \(-\frac{3}{5}\;\square\;-0.58\) b) \(-2.07\;\square\;-2.7\) c) \(-\frac{1}{8}\;\square\;-0.125\) d) \(-0.72\;\square\;-\frac{7}{10}\)

Hints

- Convert fractions to decimals when that makes a pair easier to compare. - On a number line, the value farther right is greater. - For negative numbers, a value farther from zero on the left is smaller.

Solution

1. For a), \(-\frac{3}{5}=-0.6\). Since \(-0.6<-0.58\), the correct symbol is \(<\). 2. For b), \(-2.07\) is closer to zero than \(-2.7\), so \(-2.07>-2.7\). 3. For c), \(-\frac{1}{8}=-0.125\), so the values are equal. 4. For d), \(-\frac{7}{10}=-0.7\). Since \(-0.72\) lies to the left of \(-0.7\), \(-0.72<-\frac{7}{10}\).

Answer

a) \(-\frac{3}{5}<-0.58\) b) \(-2.07>-2.7\) c) \(-\frac{1}{8}=-0.125\) d) \(-0.72<-\frac{7}{10}\)
Compare and order rational numbers 24
Order the numbers from least to greatest: \(-5.4\), \(-5.04\), \(-5.44\), \(-5.404\), \(-5\)

Hints

- Add trailing zeros to align decimal places. - Think about the positions on a number line. - A negative number with greater absolute value is smaller.

Solution

1. Write the values with the same number of decimal places: \(-5.400\), \(-5.040\), \(-5.440\), \(-5.404\), and \(-5.000\). 2. For negative numbers, the value with the greater absolute value is smaller. 3. Therefore, \(-5.44 < -5.404 < -5.4 < -5.04 < -5\).

Answer

\(-5.44 < -5.404 < -5.4 < -5.04 < -5\)
Compare and order rational numbers 25
Order the four values from least to greatest. \(0.35\); \(\quad \frac{3}{8}\); \(\quad 36\%\); \(\quad \frac{1}{3}\)

Hints

- Choose one form—fraction, decimal, or percent—and rewrite all four values in that form. - To write a fraction as a decimal, divide the numerator by the denominator. - To write a decimal as a percent, multiply by \(100\) and include the percent sign.

Solution

1. Convert the values to decimals or percents: \(0.35 = 35\%\) \(\frac{3}{8} = 3 \div 8 = 0.375 = 37.5\%\) \(36\% = 0.36\) \(\frac{1}{3} = 1 \div 3 = 0.\overline{3} \approx 33.3\%\) 2. Compare the equivalent percents: \(33.\overline{3}\% < 35\% < 36\% < 37.5\%\). 3. Therefore, the original values are ordered as \(\frac{1}{3} < 0.35 < 36\% < \frac{3}{8}\).

Answer

\(\frac{1}{3} < 0.35 < 36\% < \frac{3}{8}\)
Compare and order rational numbers 26
Consider the integers \(-22,-17,-35,-9,-21,2\). Which numbers lie to the left of \(-20\) on a number line? List only those numbers, ordered from least to greatest using \(<\).

Hints

- “To the left” means “less than.” - Select every number less than \(-20\). - Order only the selected numbers.

Solution

1. Numbers to the left of \(-20\) are less than \(-20\). The qualifying numbers are \(-22,-35,-21\). 2. From least to greatest, they are \(-35<-22<-21\).

Answer

\(-35<-22<-21\)
Compare and order rational numbers 27
Order the integers from least to greatest: \(-110,-101,-111,-10,-11,-100,-1\).

Hints

- Picture the numbers on a number line. - Which number lies farthest to the left? - For negative numbers, greater distance below zero means a lesser value.

Solution

1. For negative integers, the number with the greater absolute value is less. 2. Comparing their positions on a number line gives \(-111<-110<-101<-100<-11<-10<-1\).

Answer

\(-111<-110<-101<-100<-11<-10<-1\)
Compare and order rational numbers 28
Insert \(<\), \(>\), or \(=\) to make each statement true. a) \(-45\mathbin{\square}-54\) b) \(-12\mathbin{\square}0\) c) \(-100\mathbin{\square}-99\) d) \(7\mathbin{\square}-70\) e) \(-1\mathbin{\square}-1\) f) \(-18\mathbin{\square}-19\)

Hints

- Picture each pair on a number line. - For negative numbers, how does distance from zero affect order? - How does any negative number compare with zero?

Solution

1. \(-45>-54\) because \(-45\) lies to the right of \(-54\). 2. \(-12<0\) because every negative number is less than zero. 3. \(-100<-99\) because \(-100\) lies farther left. 4. \(7>-70\) because every positive number is greater than every negative number. 5. \(-1=-1\) because the values are identical. 6. \(-18>-19\) because \(-18\) lies closer to zero.

Answer

a) \(-45>-54\) b) \(-12<0\) c) \(-100<-99\) d) \(7>-70\) e) \(-1=-1\) f) \(-18>-19\)
Compare and order rational numbers 29
Find the integers that satisfy each condition. a) List all integers greater than \(-5\) and less than \(1\). b) Which numbers in the list lie strictly between \(-12\) and \(-7\)? \(-13,-11,-10,-9,-8,-7,-6\)

Hints

- “Strictly between” does not include the endpoints. - Move through the integers in order on a number line. - Distinguish \(<\) from \(\leq\).

Solution

1. Part a) requires \(-5<x<1\), so the integers are \(-4,-3,-2,-1,0\). 2. Part b) requires \(-12<x<-7\). The numbers from the list that satisfy both inequalities are \(-11,-10,-9,-8\).

Answer

a) \(-4,-3,-2,-1,0\) b) \(-11,-10,-9,-8\)
Compare and order rational numbers 30
A historical timeline model assigns these signed coordinates to five events: - Event \(P\): \(1048\) - Event \(Q\): \(-384\) - Event \(R\): \(1918\) - Event \(S\): \(10\) - Event \(T\): \(1643\) Using only the signed coordinates, order the event labels from earliest (least coordinate) to latest (greatest coordinate).

Hints

- Ignore outside historical knowledge and compare only the signed coordinates shown. - A negative coordinate is less than every positive coordinate. - Among positive coordinates, compare place values from left to right.

Solution

1. Order the signed coordinates from least to greatest: \(-384<10<1048<1643<1918\). 2. Match each coordinate to its event label. 3. The event order is \(Q,S,P,T,R\).

Answer

\(Q,S,P,T,R\)
Compare and order rational numbers 31
Order the integers from least to greatest: \(12,-18,-3,7,-25,0,4\).

Hints

- Picture the integers on a number line. - Negative numbers are less than zero and positive numbers. - Among negative numbers, the value farther from zero is less.

Solution

1. Order the negative numbers: \(-25<-18<-3\). 2. Zero is greater than all negative numbers and less than all positive numbers. 3. Order the positive numbers: \(4<7<12\). 4. Combining the groups gives \(-25<-18<-3<0<4<7<12\).

Answer

\(-25<-18<-3<0<4<7<12\)
Compare and order rational numbers 32
Place the integers \(-105,-210,105,-120,201,0\) in the boxes to make a true inequality chain. \(\square<\square<\square<\square<\square<\square\)

Hints

- Compare place values and absolute values carefully. - Among negative integers, a greater absolute value means a lesser number. - Place zero between the negative and positive values.

Solution

1. Order the negative integers: \(-210<-120<-105\). 2. Place zero between the negative and positive integers. 3. Order the positive integers: \(105<201\). 4. The completed chain is \(-210<-120<-105<0<105<201\).

Answer

\(-210<-120<-105<0<105<201\)
Compare and order rational numbers 33
Order these five values from least to greatest using \(<\). - The integer immediately before \(-10\) - The integer \(-10\) - The integer immediately after \(-10\) - The integer immediately before \(-12\) - The integer \(0\)

Hints

- First write the integer represented by each description. - Which value lies farthest left on a number line? - Among negative integers, a greater absolute value means a lesser number.

Solution

1. The integer before \(-10\) is \(-11\), the integer after \(-10\) is \(-9\), and the integer before \(-12\) is \(-13\). 2. Order the resulting values: \(-13<-11<-10<-9<0\).

Answer

\(-13<-11<-10<-9<0\)
Compare and order rational numbers 34
Compare each pair of numbers with each other and with \(0\). Write each result as an inequality chain of the form \(a<b<c\). a) \(-25\) and \(-17\) b) \(14\) and \(-4\) c) \(-1\) and \(1\)

Hints

- Negative numbers lie to the left of zero, and positive numbers lie to the right. - Among negative numbers, the one farther from zero is less. - The pointed side of \(<\) faces the lesser value.

Solution

1. Both numbers in part a) are negative, and \(-25\) lies farther left than \(-17\). Therefore, \(-25<-17<0\). 2. In part b), the negative number lies below zero and the positive number lies above zero. Therefore, \(-4<0<14\). 3. In part c), \(-1\) is below zero and \(1\) is above zero. Therefore, \(-1<0<1\).

Answer

a) \(-25<-17<0\) b) \(-4<0<14\) c) \(-1<0<1\)
Compare and order rational numbers 35
a) For each integer \(-1\), \(-50\), and \(-199\), write the integer immediately before it and the integer immediately after it. b) Replace each box with \(<\), \(>\), or \(=\). \(-45\mathbin{\square}-54\) \(-12\mathbin{\square}2\) \(0\mathbin{\square}-7\) \(-101\mathbin{\square}-100\)

Hints

- The integer immediately before a number is one unit to its left. - The integer immediately after a number is one unit to its right. - Compare each pair by imagining its position on a number line.

Solution

1. One unit before and after \(-1\) are \(-2\) and \(0\). One unit before and after \(-50\) are \(-51\) and \(-49\). One unit before and after \(-199\) are \(-200\) and \(-198\). 2. Comparing positions on a number line gives \(-45>-54\), \(-12<2\), \(0>-7\), and \(-101<-100\).

Answer

a) For \(-1\): before \(-2\), after \(0\); for \(-50\): before \(-51\), after \(-49\); for \(-199\): before \(-200\), after \(-198\) b) \(-45>-54\); \(-12<2\); \(0>-7\); \(-101<-100\)
Compare and order rational numbers 36
Compare each pair by converting both values to the same form. Insert \(<\), \(>\), or \(=\). a) \(\frac{3}{4}\ \square\ 0.7\) b) \(0.12\ \square\ \frac{1}{8}\) c) \(2\frac{1}{2}\ \square\ 2.50\) d) \(0.33\ \square\ \frac{1}{3}\) e) \(\frac{9}{20}\ \square\ 0.45\)

Hints

- Convert each fraction to a decimal. - Remember that a repeating decimal continues beyond the digits shown. - Add trailing zeros when comparing decimal place values.

Solution

1. \(\frac{3}{4}=0.75\), so \(\frac{3}{4}>0.7\). 2. \(\frac{1}{8}=0.125\), so \(0.12<\frac{1}{8}\). 3. \(2\frac{1}{2}=2.5=2.50\). 4. \(\frac{1}{3}=0.333\ldots\), so \(0.33<\frac{1}{3}\). 5. \(\frac{9}{20}=\frac{45}{100}=0.45\), so the values are equal.

Answer

a) \(\frac{3}{4}>0.7\) b) \(0.12<\frac{1}{8}\) c) \(2\frac{1}{2}=2.50\) d) \(0.33<\frac{1}{3}\) e) \(\frac{9}{20}=0.45\)
Compare and order rational numbers 37
Consider \(-4.2\), \(-4\frac{1}{4}\), \(-4.08\), \(-4\frac{3}{10}\), and \(-4.19\). a) Which number is least? b) Which number is greatest?

Hints

- Convert the mixed numbers to decimals. - Add trailing zeros to align decimal places. - For negative numbers, greater absolute value means a smaller value. - The number closest to zero is greatest.

Solution

1. Convert the mixed numbers: \(-4\frac{1}{4} = -4.25\) and \(-4\frac{3}{10} = -4.3\). 2. Compare \(-4.20\), \(-4.25\), \(-4.08\), \(-4.30\), and \(-4.19\). 3. The least number has the greatest absolute value, so it is \(-4.3 = -4\frac{3}{10}\). 4. The greatest number is closest to zero, so it is \(-4.08\).

Answer

a) \(-4\frac{3}{10}\) b) \(-4.08\)
Compare and order rational numbers 38
Compare \(-\frac{2}{5}\) and \(-\frac{2}{7}\). Which is smaller? Explain why looking only at the denominators can be misleading.

Hints

- Think about how the size of a fifth compares with a seventh. - Picture the two negative fractions on a number line. - Which one lies farther left?

Solution

1. Among positive fractions, \(\frac{2}{5}>\frac{2}{7}\) because fifths are larger than sevenths. 2. Making both fractions negative reverses their order. 3. Therefore, \(-\frac{2}{5}<-\frac{2}{7}\).

Answer

\(-\frac{2}{5}\) is smaller. Since \(\frac{2}{5}>\frac{2}{7}\), its negative is farther left on the number line.
Compare and order rational numbers 39
Are \(0.125\), \(\frac{1}{8}\), and \(12.5\%\) three different amounts or the same amount? Show a calculation that proves your answer.

Hints

- Write the fraction as a decimal. - Remember that percent means per hundred. - Decide whether the three values describe one point on the number line.

Solution

1. \(\frac{1}{8}=0.125\) by division. 2. \(12.5\%=\frac{12.5}{100}=0.125\). 3. All three expressions name the same number.

Answer

They are equal. \(\frac{1}{8}=0.125\) and \(12.5\%=\frac{12.5}{100}=0.125\).
Compare and order rational numbers 40
Without changing the fractions to percents, decide whether \(\frac{7}{12}\) or \(\frac{5}{9}\) is greater. Explain the method you chose.

Hints

- Are these fractions on the same side of \(\frac{1}{2}\)? - If a benchmark does not settle the comparison, can you give both fractions equal-sized parts? - Check the comparison without rounding either fraction.

Solution

1. Compare the fractions by making a common denominator: \(\frac{7}{12}=\frac{21}{36}\) and \(\frac{5}{9}=\frac{20}{36}\). 2. Since \(21>20\), \(\frac{7}{12}>\frac{5}{9}\).

Answer

\(\frac{7}{12}\) is greater, because \(\frac{21}{36}>\frac{20}{36}\).
Compare and order rational numbers 41
What number is halfway between A and B? Explain how you know.
Figure for problem 559412

Hints

- Use the spacing of the ticks to read each endpoint. - Find the distance between the two points. - The halfway point is the same distance from both endpoints.

Solution

1. From the scale, A is at \(-\frac{3}{4}\) and B at \(-\frac{1}{4}\). 2. They are \(\frac{1}{2}\) unit apart. 3. Half the gap is \(\frac{1}{4}\), so the midpoint is \(-\frac{3}{4}+\frac{1}{4}=-\frac{1}{2}\).

Answer

\(-\frac{1}{2}\), because it is \(\frac{1}{4}\) unit from each of \(-\frac{3}{4}\) and \(-\frac{1}{4}\).
Compare and order rational numbers 42
Maya says, “There are no fractions between \(\frac{2}{5}\) and \(\frac{3}{5}\) because there is no whole number between \(2\) and \(3\).” Rewrite both fractions in twentieths. Give two different fractions strictly between them, and explain Maya's mistake.

Hints

- Mark the two original fractions on a number line. - When one fifth is split into four equal parts, how many small intervals appear between the marks? - Check that both choices lie inside the interval rather than at its ends.

Solution

1. Rewrite the endpoints: \(\frac{2}{5}=\frac{8}{20}\) and \(\frac{3}{5}=\frac{12}{20}\). 2. For example, \(\frac{9}{20}\) and \(\frac{11}{20}\) both lie strictly between the endpoints. 3. Maya looked only at fifths. Changing to smaller equal parts gives more possible numerators between the same endpoints.

Answer

\(\frac{2}{5}=\frac{8}{20}<\frac{9}{20}<\frac{11}{20}<\frac{12}{20}=\frac{3}{5}\). Maya's mistake is assuming fifths are the only fractions allowed between the endpoints.
Compare and order rational numbers 43
Order these values from least to greatest. Justify your order by writing all values in the same form, such as decimals or percentages. \(\frac{3}{8}\), \(35\%\), \(0.4\), \(\frac{2}{5}\)

Hints

- Convert every value to either a decimal or a percent. - Compare the values after they are written in the same form. - Check whether any two representations have the same value.

Solution

1. Write all values as decimals: \(\frac{3}{8}=0.375\), \(35\%=0.35\), \(0.4=0.4\), and \(\frac{2}{5}=0.4\). 2. Compare the decimals: \(0.35<0.375<0.4=0.4\). 3. Therefore, \(35\%<\frac{3}{8}<0.4=\frac{2}{5}\).

Answer

\(35\%<\frac{3}{8}<0.4=\frac{2}{5}\)
Compare and order rational numbers 44
Order these numbers from least to greatest: \(3\frac{1}{4}\), \(\frac{10}{3}\), \(\frac{17}{5}\), \(3\frac{1}{2}\)

Hints

- Write all four numbers in the same form. - Use a common denominator or convert all values to decimals. - Compare the equivalent values before writing the original numbers in order.

Solution

1. Convert the mixed numbers to improper fractions: \(3\frac{1}{4}=\frac{13}{4}\) and \(3\frac{1}{2}=\frac{7}{2}\). 2. Use the common denominator \(60\): \(\frac{13}{4}=\frac{195}{60}\), \(\frac{10}{3}=\frac{200}{60}\), \(\frac{17}{5}=\frac{204}{60}\), and \(\frac{7}{2}=\frac{210}{60}\). 3. Since \(195<200<204<210\), the order is \(3\frac{1}{4}<\frac{10}{3}<\frac{17}{5}<3\frac{1}{2}\).

Answer

\(3\frac{1}{4}<\frac{10}{3}<\frac{17}{5}<3\frac{1}{2}\)
Compare and order rational numbers 45
Rewrite the values in each pair in the same form. Then replace each blank with \(<\), \(>\), or \(=\). a) \(3\frac{4}{7}\quad\square\quad\frac{24}{7}\) b) \(\frac{45}{12}\quad\square\quad3\frac{3}{4}\) c) \(6\frac{2}{5}\quad\square\quad\frac{62}{10}\)

Hints

- Write each mixed number as an improper fraction if helpful. - Try to give the fractions in a pair the same denominator. - Compare after you have expressed both values in one form.

Solution

1. \(3\frac{4}{7}=\frac{25}{7}>\frac{24}{7}\), so a) is \(>\). 2. \(\frac{45}{12}=\frac{15}{4}=3\frac{3}{4}\), so b) is \(=\). 3. \(6\frac{2}{5}=\frac{64}{10}>\frac{62}{10}\), so c) is \(>\).

Answer

a) \(3\frac{4}{7}=\frac{25}{7}>\frac{24}{7}\) b) \(\frac{45}{12}=\frac{15}{4}\) and \(3\frac{3}{4}=\frac{15}{4}\), so \(=\). c) \(6\frac{2}{5}=\frac{64}{10}>\frac{62}{10}\)
Compare and order rational numbers 46
Compare \(\frac{25}{4}\) and \(\frac{31}{5}\). First write both as mixed numbers. Which fraction is closer to the next whole number? Justify your answer by comparing how much each fraction needs to reach that whole number.

Hints

- Find the next whole number greater than each fraction. - Subtract the fractional part from \(1\) to find each distance. - The smaller distance identifies the closer number. - Use a common denominator to compare the distances.

Solution

1. Convert \(\frac{25}{4}\): \(25\div4=6\) remainder \(1\), so \(\frac{25}{4}=6\frac{1}{4}\). It needs \(1-\frac{1}{4}=\frac{3}{4}\) to reach \(7\). 2. Convert \(\frac{31}{5}\): \(31\div5=6\) remainder \(1\), so \(\frac{31}{5}=6\frac{1}{5}\). It needs \(1-\frac{1}{5}=\frac{4}{5}\) to reach \(7\). 3. Use a common denominator: \(\frac{3}{4}=\frac{15}{20}\) and \(\frac{4}{5}=\frac{16}{20}\). Since \(\frac{15}{20}<\frac{16}{20}\), \(\frac{25}{4}\) is closer to \(7\).

Answer

\(\frac{25}{4}=6\frac{1}{4}\) is closer to \(7\) because its distance, \(\frac{3}{4}\), is less than \(\frac{4}{5}\), the distance from \(\frac{31}{5}=6\frac{1}{5}\) to \(7\).
Compare and order rational numbers 47
For each pair, decide which fraction is greater. Explain your reasoning without using long division. You may compare each fraction with \(\frac{1}{2}\) or \(1\), compare distances from \(1\), or rewrite the fractions with equal numerators. a) \(\frac{7}{8}\) and \(\frac{8}{9}\) b) \(\frac{4}{9}\) and \(\frac{5}{11}\) c) \(\frac{12}{5}\) and \(\frac{15}{7}\)

Hints

- Compare how far fractions near \(1\) are from \(1\). - Try rewriting a pair with equal numerators. - For improper fractions, compare their whole-number and fractional parts.

Solution

1. For a), \(\frac{7}{8}=1-\frac{1}{8}\) and \(\frac{8}{9}=1-\frac{1}{9}\). Since \(\frac{1}{9}<\frac{1}{8}\), \(\frac{8}{9}\) is closer to \(1\), so \(\frac{8}{9}>\frac{7}{8}\). 2. For b), rewrite with numerator \(20\): \(\frac{4}{9}=\frac{20}{45}\) and \(\frac{5}{11}=\frac{20}{44}\). With equal numerators, the smaller denominator gives the greater fraction, so \(\frac{5}{11}>\frac{4}{9}\). 3. For c), \(\frac{12}{5}=2\frac{2}{5}\) and \(\frac{15}{7}=2\frac{1}{7}\). Since \(\frac{2}{5}>\frac{1}{7}\), \(\frac{12}{5}>\frac{15}{7}\).

Answer

a) \(\frac{8}{9}>\frac{7}{8}\) b) \(\frac{5}{11}>\frac{4}{9}\) c) \(\frac{12}{5}>\frac{15}{7}\)
Compare and order rational numbers 48
Insert \(<\), \(>\), or \(=\) in each blank. Briefly justify each comparison. a) \(\frac{7}{15}\ \_\_\_\ \frac{7}{13}\) b) \(2\frac{3}{5}\ \_\_\_\ \frac{13}{5}\) c) \(\frac{8}{9}\ \_\_\_\ \frac{9}{10}\)

Hints

- With equal numerators, compare the denominators. - Convert the mixed number to an improper fraction. - For fractions close to \(1\), compare the missing unit fractions.

Solution

1. For a), the fractions have equal numerators. The fraction with the larger denominator is smaller, so \(\frac{7}{15}<\frac{7}{13}\). 2. For b), \(2\frac{3}{5}=\frac{2\times5+3}{5}=\frac{13}{5}\), so the values are equal. 3. For c), \(\frac{8}{9}=1-\frac{1}{9}\) and \(\frac{9}{10}=1-\frac{1}{10}\). Since \(\frac{1}{10}<\frac{1}{9}\), \(\frac{9}{10}\) is closer to \(1\), so \(\frac{8}{9}<\frac{9}{10}\).

Answer

a) \(\frac{7}{15}<\frac{7}{13}\) b) \(2\frac{3}{5}=\frac{13}{5}\) c) \(\frac{8}{9}<\frac{9}{10}\)
Compare and order rational numbers 49
Is there a fraction with denominator \(8\) that lies between \(\frac{2}{5}\) and \(\frac{3}{5}\)? If so, give the smallest such fraction.

Hints

- List the eighths near \(\frac{2}{5}\) and \(\frac{3}{5}\). - Compare each nearby eighth with the two boundary fractions. - Stop at the first eighth that is greater than the lower bound and less than the upper bound.

Solution

1. Fractions with denominator \(8\) near this interval are \(\frac{3}{8}\), \(\frac{4}{8}\), and \(\frac{5}{8}\). 2. \(\frac{3}{8}=0.375\), which is less than \(\frac{2}{5}=0.4\). 3. \(\frac{4}{8}=\frac{1}{2}=0.5\), and \(0.4<0.5<0.6\), where \(\frac{3}{5}=0.6\). 4. Therefore, \(\frac{4}{8}\) is the smallest fraction with denominator \(8\) in the interval.

Answer

\(\frac{4}{8}\), which simplifies to \(\frac{1}{2}\)
Compare and order rational numbers 50
Compare each pair without finding a common denominator. Use logical comparisons such as mixed-number form, distance from \(1\), or equivalent decimals. a) \(2\frac{3}{5}\) and \(\frac{11}{4}\) b) \(\frac{9}{10}\) and \(\frac{10}{11}\) c) \(0.45\) and \(\frac{4}{10}\)

Hints

- Convert an improper fraction to a mixed number when that makes the whole-number parts easy to compare. - For fractions near \(1\), compare the amounts missing from \(1\). - Write tenths as decimals when comparing with a decimal.

Solution

1. For a), \(\frac{11}{4}=2\frac{3}{4}\). Since \(\frac{3}{5}<\frac{3}{4}\), \(2\frac{3}{5}<\frac{11}{4}\). 2. For b), \(\frac{9}{10}=1-\frac{1}{10}\) and \(\frac{10}{11}=1-\frac{1}{11}\). Since \(\frac{1}{11}<\frac{1}{10}\), \(\frac{10}{11}\) is closer to \(1\), so \(\frac{9}{10}<\frac{10}{11}\). 3. For c), \(\frac{4}{10}=0.40\). Since \(0.45>0.40\), \(0.45>\frac{4}{10}\).

Answer

a) \(2\frac{3}{5}<\frac{11}{4}\) b) \(\frac{9}{10}<\frac{10}{11}\) c) \(0.45>\frac{4}{10}\)
Compare and order rational numbers 51
Let \(a = -1.2\), \(b = \left\lvert-\frac{3}{4}\right\rvert\), \(c = -\frac{1}{2}\), and \(d = \lvert0.6\rvert\). Order the values from least to greatest using \(<\).

Hints

- Evaluate the absolute values first. - Convert the fraction to a decimal or the decimals to fractions. - On a number line, a value farther left is smaller.

Solution

1. Evaluate the absolute values: \(b = \frac{3}{4} = 0.75\) and \(d = 0.6\). 2. Write all values as decimals: \(a = -1.2\), \(b = 0.75\), \(c = -0.5\), and \(d = 0.6\). 3. Compare the negative values: \(-1.2 < -0.5\). 4. Compare the positive values: \(0.6 < 0.75\). 5. Therefore, \(a < c < d < b\).

Answer

\(-1.2 < -\frac{1}{2} < \lvert0.6\rvert < \left\lvert-\frac{3}{4}\right\rvert\)
Compare and order rational numbers 52
Consider the numbers \(-2.5\), \(4\), \(0\), \(-\frac{8}{2}\), \(\frac{1}{2}\), \(-1\), and \(1.2\). a) Compare \(-2.5\) and \(-\frac{8}{2}\) using \(<\), \(>\), or \(=\). b) Order all the numbers from least to greatest using \(<\).

Hints

- Simplify \(-\frac{8}{2}\) before comparing. - For negative values, the point farther left is smaller. - Convert \(\frac{1}{2}\) to a familiar equivalent form if helpful before ordering the whole list.

Solution

1. Simplify \(-\frac{8}{2}=-4\). 2. Since \(-2.5\) is to the right of \(-4\) on a number line, \(-2.5>-\frac{8}{2}\). 3. For the full ordering, compare the values \(-2.5,4,0,-4,0.5,-1,1.2\). 4. The order is \(-4<-2.5<-1<0<0.5<1.2<4\).

Answer

a) \(-2.5>-\frac{8}{2}\) b) \(-\frac{8}{2}<-2.5<-1<0<\frac{1}{2}<1.2<4\)
Compare and order rational numbers 53
Let \(a = -3\frac{4}{9}\) and \(b = -3\frac{5}{11}\). Which number lies farther to the right on the number line? Justify your answer by comparing absolute values.

Hints

- For two negative numbers, the one closer to zero is greater. - Compare the absolute values. - Rewrite \(\frac{4}{9}\) and \(\frac{5}{11}\) with a common denominator.

Solution

1. The absolute values are \(\lvert a\rvert = 3\frac{4}{9}\) and \(\lvert b\rvert = 3\frac{5}{11}\). 2. Compare the fractional parts using denominator \(99\): \(\frac{4}{9} = \frac{44}{99}\) and \(\frac{5}{11} = \frac{45}{99}\). 3. Since \(\frac{44}{99} < \frac{45}{99}\), \(\lvert a\rvert < \lvert b\rvert\). 4. Of two negative numbers, the one with the smaller absolute value is closer to zero and lies farther right. Therefore, \(a\) lies farther right.

Answer

\(a = -3\frac{4}{9}\) lies farther right because \(\left|-3\frac{4}{9}\right| < \left|-3\frac{5}{11}\right|\).
Compare and order rational numbers 54
Order the following values from least to greatest. Convert them to one common form and show your work. \(0.45\); \(4.5\%\); \(\frac{2}{5}\); \(\frac{1}{20}\); \(44\%\)

Hints

- Values are easier to compare when they are written in the same form. - You could write every value as a decimal or as a percent. - Pay close attention to place value in the decimals.

Solution

1. Convert each value to a decimal: \(0.45 = 0.45\) \(4.5\% = 0.045\) \(\frac{2}{5} = \frac{4}{10} = 0.4\) \(\frac{1}{20} = \frac{5}{100} = 0.05\) \(44\% = 0.44\) 2. Compare the decimals: \(0.045 < 0.05 < 0.4 < 0.44 < 0.45\). 3. Replace the decimals with the original values: \(4.5\% < \frac{1}{20} < \frac{2}{5} < 44\% < 0.45\).

Answer

\(4.5\% < \frac{1}{20} < \frac{2}{5} < 44\% < 0.45\)
Compare and order rational numbers 55
Order the rational numbers from least to greatest using \(<\): \(-0.6\), \(\frac{1}{2}\), \(-\frac{5}{8}\), \(0.45\), \(-\frac{1}{10}\)

Hints

- Convert all values to decimals or all to fractions. - Order negative and positive values separately first. - A value farther left on the number line is smaller. - Trailing zeros can help align decimal places.

Solution

1. Convert the fractions to decimals: \(\frac{1}{2} = 0.5\), \(-\frac{5}{8} = -0.625\), and \(-\frac{1}{10} = -0.1\). 2. Order the negative values: \(-0.625 < -0.6 < -0.1\). 3. Order the positive values: \(0.45 < 0.5\). 4. Combining the groups gives \(-\frac{5}{8} < -0.6 < -\frac{1}{10} < 0.45 < \frac{1}{2}\).

Answer

\(-\frac{5}{8} < -0.6 < -\frac{1}{10} < 0.45 < \frac{1}{2}\)
Compare and order rational numbers 56
Let \(a = -\frac{7}{4}\) and \(b = -1.8\). 1. Which number lies farther to the right on the number line? 2. Which number has the greater absolute value? Justify both answers with calculations.

Hints

- Convert the fraction to a decimal. - The greater number lies farther right on the number line. - Absolute value is distance from zero. - For negative numbers, being greater and having greater absolute value are not the same.

Solution

1. Convert \(a\): \(-\frac{7}{4} = -1.75\). 2. Since \(-1.75 > -1.8\), \(a\) lies farther to the right. 3. The absolute values are \(\lvert a\rvert = 1.75\) and \(\lvert b\rvert = 1.8\). 4. Since \(1.8 > 1.75\), \(b\) has the greater absolute value.

Answer

1. \(a = -\frac{7}{4}\) lies farther right. 2. \(b = -1.8\) has the greater absolute value.
Compare and order rational numbers 57
Consider \(\frac{3}{8}\), \(0.3\), \(\frac{2}{5}\), and \(0.38\). a) Convert the fractions to decimals and order all four numbers from least to greatest. b) Give one decimal strictly between the two greatest values from part a).

Hints

- Convert both fractions to decimals first. - Compare tenths, hundredths, and thousandths in order. - Write \(0.4\) as \(0.40\) if that helps you find a number between the last two values.

Solution

1. Convert the fractions: \(\frac{3}{8} = 0.375\) and \(\frac{2}{5} = 0.4\). 2. Compare the decimals: \(0.3 < 0.375 < 0.38 < 0.4\). 3. The two greatest values are \(0.38\) and \(0.4\). One decimal between them is \(0.39\).

Answer

a) \(\frac{3}{8}=0.375\), \(\frac{2}{5}=0.4\); \(0.3<0.375<0.38<0.4\). b) Answers will vary. One possible answer is \(0.39\).
Compare and order rational numbers 58
Order the negative rational numbers from greatest to least: \(-0.4\), \(-\frac{4}{9}\), \(-0.45\), \(-\frac{3}{7}\), \(-0.44\)

Hints

- Convert the fractions to decimals. - For negative numbers, the value closer to zero is greater. - Compare absolute values in the reverse order. - Use enough decimal places to distinguish close values.

Solution

1. Convert the fractions: \(-\frac{3}{7} \approx -0.4286\) and \(-\frac{4}{9} = -0.4444\ldots\). 2. Compare the absolute values: \(0.4 < 0.4286 < 0.44 < 0.4444\ldots < 0.45\). 3. For negative numbers, the value with the smaller absolute value is greater. 4. Therefore, \(-0.4 > -\frac{3}{7} > -0.44 > -\frac{4}{9} > -0.45\).

Answer

\(-0.4 > -\frac{3}{7} > -0.44 > -\frac{4}{9} > -0.45\)
Compare and order rational numbers 59
Order the rational numbers from least to greatest: \(-0.95\), \(-\frac{11}{12}\), \(-\frac{9}{10}\), \(-0.915\), \(-\frac{12}{13}\)

Hints

- All the values lie between \(-1\) and \(-0.9\). - Convert the fractions to enough decimal places to compare them. - For negative values, the one closer to \(-1\) is smaller. - Compare absolute values in reverse order.

Solution

1. Convert the fractions to decimals: \(-\frac{9}{10} = -0.9\), \(-\frac{11}{12} \approx -0.9167\), and \(-\frac{12}{13} \approx -0.9231\). 2. Compare the values. For negative numbers, the value with the greater absolute value is smaller. 3. The order is \(-0.95 < -0.9231\ldots < -0.9166\ldots < -0.915 < -0.9\). 4. Using the original forms, \(-0.95 < -\frac{12}{13} < -\frac{11}{12} < -0.915 < -\frac{9}{10}\).

Answer

\(-0.95 < -\frac{12}{13} < -\frac{11}{12} < -0.915 < -\frac{9}{10}\)
Compare and order rational numbers 60
Give two different decimals in each open interval. a) between \(0.4\) and \(0.5\) b) between \(-1.2\) and \(-1.1\) c) between \(\frac{3}{4}\) and \(0.8\)

Hints

- Add trailing zeros to make place values easier to compare. - Remember the order of negative numbers on a number line. - Convert \(\frac{3}{4}\) to a decimal before choosing values.

Solution

1. For a), examples include \(0.41\) and \(0.45\), since \(0.4 < 0.41 < 0.45 < 0.5\). 2. For b), examples include \(-1.19\) and \(-1.15\), since \(-1.2 < -1.19 < -1.15 < -1.1\). 3. For c), convert \(\frac{3}{4} = 0.75\). Examples include \(0.76\) and \(0.78\).

Answer

Answers will vary. One possible set is: a) \(0.41\) and \(0.42\) b) \(-1.18\) and \(-1.12\) c) \(0.77\) and \(0.79\)
Compare and order rational numbers 61
Determine which of these numbers lie strictly between \(-\frac{1}{5}\) and \(-0.1\): \(-0.15\), \(-0.25\), \(-0.05\). Justify your choices by comparing decimal forms.

Hints

- Convert one fifth to a decimal. - Write the interval as a double inequality. - Use a number line to compare negative values.

Solution

1. Convert the fraction: \(-\frac{1}{5} = -0.2\). 2. A number \(x\) is in the interval when \(-0.2 < x < -0.1\). 3. Since \(-0.2 < -0.15 < -0.1\), \(-0.15\) is in the interval. 4. Since \(-0.25 < -0.2\), \(-0.25\) is outside the interval. 5. Since \(-0.05 > -0.1\), \(-0.05\) is outside the interval.

Answer

Only \(-0.15\) lies in the interval because \(-0.2 < -0.15 < -0.1\).
Compare and order rational numbers 62
Let \(x=-1.4\) and \(y=-1.5\). a) Without calculating, explain which number is greater. b) Give a rational number \(z\) exactly halfway between \(x\) and \(y\). c) Compare \(-\frac{7}{5}\) and \(-\frac{3}{2}\). Which fraction equals \(x\)?

Hints

- On the number line, the value farther right is greater. - For the halfway point, first find how far apart the two decimals are. - Convert each fraction to a decimal for part c.

Solution

1. For a), \(-1.4\) lies to the right of \(-1.5\) on a number line, so \(x>y\). 2. For b), the points \(-1.4\) and \(-1.5\) are \(0.1\) unit apart. Half of \(0.1\) is \(0.05\), so the halfway point is \(-1.45\). 3. For c), \(-\frac{7}{5}=-1.4\) and \(-\frac{3}{2}=-1.5\). 4. Thus, \(-\frac{7}{5}>-\frac{3}{2}\), and \(-\frac{7}{5}\) equals \(x\).

Answer

a) \(-1.4>-1.5\) b) \(z=-1.45\) c) \(-\frac{7}{5}>-\frac{3}{2}\); \(-\frac{7}{5}\) equals \(x\).
Compare and order rational numbers 63
Let \(A=-3.15\), \(B=-\frac{13}{4}\), \(C=-3\frac{1}{10}\), and \(D=-3.2\). Which numbers lie to the left of \(-3.1\) on a number line? Order those numbers from least to greatest.

Hints

- A number to the left on a number line is smaller. - Convert the fraction and mixed number to decimals. - For negative numbers, the value with greater absolute value is smaller.

Solution

1. Convert the fraction and mixed number: \(B=-\frac{13}{4}=-3.25\) and \(C=-3\frac{1}{10}=-3.1\). 2. Numbers to the left of \(-3.1\) are less than \(-3.1\). These are \(A=-3.15\), \(B=-3.25\), and \(D=-3.2\). Point \(C\) is exactly at \(-3.1\), so it is not included. 3. From least to greatest, \(-3.25<-3.2<-3.15\). 4. In the original forms, \(-\frac{13}{4}<-3.2<-3.15\).

Answer

\(-\frac{13}{4}<-3.2<-3.15\)
Compare and order rational numbers 64
Compare each pair. Write \(<\), \(>\), or \(=\), and justify your choice by writing both values in the same form. a) \(0.15 \quad \square \quad \frac{4}{25}\) b) \(\frac{5}{6} \quad \square \quad 83\%\) c) \(0.09 \quad \square \quad \frac{1}{11}\)

Hints

- Write both values in each pair in the same form. - For a repeating value, keep enough digits to decide the comparison. - Compare corresponding place values carefully.

Solution

1. For a), \(0.15 = 15\%\) and \(\frac{4}{25} = \frac{16}{100} = 16\%\). Since \(15\% < 16\%\), \(0.15 < \frac{4}{25}\). 2. For b), \(\frac{5}{6} = 0.8333\ldots = 83.333\ldots\%\). Since \(83.333\ldots\% > 83\%\), \(\frac{5}{6} > 83\%\). 3. For c), \(0.09 = 9\%\) and \(\frac{1}{11} = 0.0909\ldots = 9.09\ldots\%\). Since \(9\% < 9.09\ldots\%\), \(0.09 < \frac{1}{11}\).

Answer

a) \(0.15 < \frac{4}{25}\) b) \(\frac{5}{6} > 83\%\) c) \(0.09 < \frac{1}{11}\)
Compare and order rational numbers 65
Order these four numbers from least to greatest. Convert each number to a percent, rounding to the nearest tenth of a percent when needed. \(\frac{2}{9}, \quad 0.22, \quad 22.5\%, \quad \frac{1}{4}\)

Hints

- Put all four values in the requested percent form before ordering them. - Keep enough digits for any repeating value to round correctly. - Then order the results as they would appear on a number line.

Solution

1. Convert each value to a percent: \(\frac{2}{9} = 0.222\ldots \approx 22.2\%\) \(0.22 = 22\%\) \(22.5\%\) is already a percent. \(\frac{1}{4} = 0.25 = 25\%\) 2. Compare the percents: \(22\% < 22.2\% < 22.5\% < 25\%\). 3. Replace the percents with the original values: \(0.22 < \frac{2}{9} < 22.5\% < \frac{1}{4}\).

Answer

\(0.22 < \frac{2}{9} < 22.5\% < \frac{1}{4}\)
Compare and order rational numbers 66
Order the following values from least to greatest using \(<\): \(0.7\); \(\frac{3}{4}\); \(72\%\); \(\frac{13}{20}\); \(0.68\)

Hints

- Would it be easier to compare all the values as decimals or all as percents? - How can you quickly write \(\frac{3}{4}\) and \(\frac{13}{20}\) as percents? - Think about how many hundredths each value represents.

Solution

1. Write each value as a percent: \(0.7 = 70\%\) \(\frac{3}{4} = \frac{75}{100} = 75\%\) \(72\%\) is already a percent. \(\frac{13}{20} = \frac{65}{100} = 65\%\) \(0.68 = 68\%\) 2. Compare the percents: \(65\% < 68\% < 70\% < 72\% < 75\%\). 3. Replace the percents with the original values: \(\frac{13}{20} < 0.68 < 0.7 < 72\% < \frac{3}{4}\).

Answer

\(\frac{13}{20} < 0.68 < 0.7 < 72\% < \frac{3}{4}\)
Compare and order rational numbers 67
Three students compare the portions of their allowances that they saved last month. - Jordan saved \(\frac{13}{25}\) of the allowance. - Sarah saved \(54\%\) of the allowance. - Leo saved \(0.51\) of the allowance. Order the students from the smallest saved portion to the largest. Who saved the greatest portion?

Hints

- Write all three portions in the same form, such as percents. - How do you write \(0.51\) as a percent? - What can you multiply \(25\) by to get \(100\)?

Solution

1. Convert Jordan's portion: \(\frac{13}{25} = \frac{52}{100} = 52\%\). 2. Convert Leo's portion: \(0.51 = 51\%\). 3. Compare the percents: \(51\% < 52\% < 54\%\). 4. The order is Leo, Jordan, Sarah. Sarah saved the greatest portion.

Answer

Leo \((51\%)\), Jordan \((52\%)\), Sarah \((54\%)\). Sarah saved the greatest portion.
Compare and order rational numbers 68
A beverage company compares the fruit content of four drinks: - Sparkling apple drink: \(\frac{120}{200}\) - Tropical juice: \(\frac{45}{60}\) - Berry blend: \(\frac{18}{25}\) - Lemonade: \(\frac{3}{40}\) Find the fruit content of each drink as a percent. Rank the drinks from greatest to least fruit content.

Hints

- Can you simplify a fraction before writing it with denominator \(100\)? - How can you convert a fraction whose denominator does not divide \(100\) evenly? - After converting, compare the percent values.

Solution

1. Sparkling apple drink: \(\frac{120}{200} = \frac{60}{100} = 60\%\). 2. Tropical juice: \(\frac{45}{60} = \frac{3}{4} = \frac{75}{100} = 75\%\). 3. Berry blend: \(\frac{18}{25} = \frac{72}{100} = 72\%\). 4. Lemonade: \(\frac{3}{40} = 0.075 = 7.5\%\). 5. From greatest to least, the order is tropical juice, berry blend, sparkling apple drink, lemonade.

Answer

Fruit content: tropical juice \(75\%\), berry blend \(72\%\), sparkling apple drink \(60\%\), lemonade \(7.5\%\). Ranking: 1. tropical juice, 2. berry blend, 3. sparkling apple drink, 4. lemonade.
Compare and order rational numbers 69
Determine which of the following numbers lie strictly between \(25\%\) and \(\frac{2}{5}\): \(0.3\); \(\frac{7}{20}\); \(42\%\); \(0.24\); \(\frac{1}{4}\) Justify your answer by writing all the values as percents.

Hints

- What does it mean for a number to lie strictly between two values? - Write both endpoints and every test value in the same form. - Check whether a value equals an endpoint or lies inside the interval.

Solution

1. Write the endpoints as percents: the lower endpoint is \(25\%\), and \(\frac{2}{5} = \frac{40}{100} = 40\%\). 2. Convert the test values: \(0.3 = 30\%\) \(\frac{7}{20} = \frac{35}{100} = 35\%\) \(42\%\) is already a percent. \(0.24 = 24\%\) \(\frac{1}{4} = \frac{25}{100} = 25\%\) 3. Only \(30\%\) and \(35\%\) are greater than \(25\%\) and less than \(40\%\). The value \(25\%\) is an endpoint, so it is not strictly between the endpoints.

Answer

\(0.3\), which is \(30\%\), and \(\frac{7}{20}\), which is \(35\%\), lie strictly between \(25\%\) and \(\frac{2}{5} = 40\%\).
Compare and order rational numbers 70
Compare these four portions: \(\frac{3}{4}\), \(0.72\), \(78\%\), and \(\frac{19}{25}\). Which portion is greatest, and which is least? Also find the difference between them in percentage points.

Hints

- Which form makes all four values easiest to compare? - Subtract the least percent from the greatest percent.

Solution

1. Write each portion as a percent: \(\frac{3}{4} = \frac{75}{100} = 75\%\) \(0.72 = 72\%\) \(78\%\) is already a percent. \(\frac{19}{25} = \frac{76}{100} = 76\%\) 2. Compare the values: \(72\% < 75\% < 76\% < 78\%\). 3. The greatest portion is \(78\%\), and the least portion is \(0.72\), or \(72\%\). 4. The difference is \(78 - 72 = 6\) percentage points.

Answer

The greatest portion is \(78\%\). The least portion is \(0.72\). The difference is \(6\) percentage points.
Compare and order rational numbers 71
The amount of a mineral was measured in four water samples. Order the samples from the lowest concentration to the highest, and identify the greatest concentration. Sample A: \(0.28\%\) Sample B: \(0.0022\) Sample C: \(\frac{1}{450}\) Sample D: \(\frac{5}{2000}\)

Hints

- Convert all four quantities to decimals before comparing them. - Divide the numerator by the denominator for each fraction. - Align decimal places carefully when ordering the values.

Solution

1. Convert each concentration to a decimal. Sample A: \(0.28\% = 0.0028\) Sample B: \(0.0022\) Sample C: \(\frac{1}{450} = 0.002\overline{2}\) Sample D: \(\frac{5}{2000} = 0.0025\) 2. Compare the decimals: \(0.0022 < 0.002\overline{2} < 0.0025 < 0.0028\). 3. Therefore, the order is Sample B, Sample C, Sample D, Sample A. Sample A has the greatest concentration.

Answer

From lowest to highest: Sample B, Sample C, Sample D, Sample A. Sample A has the greatest concentration.
Compare and order rational numbers 72
An alloy contains several precious metals. The gold portion is \(\frac{3}{800}\), the silver portion is \(0.35\%\), and the platinum portion is \(0.004\). A jeweler claims, “Platinum makes up the greatest portion of the alloy.” Check the claim by writing all three portions as decimals and comparing them.

Hints

- Convert every portion to the same form. - Write the percent as a decimal. - Divide the numerator by the denominator to convert the fraction.

Solution

1. The gold portion is \(\frac{3}{800} = 0.00375\). 2. The silver portion is \(0.35\% = 0.0035\). 3. The platinum portion is already written as \(0.004\). 4. Since \(0.004 > 0.00375 > 0.0035\), platinum has the greatest portion. The jeweler’s claim is correct.

Answer

The jeweler’s claim is correct. Platinum has the greatest portion because \(0.004 > 0.00375 > 0.0035\).
Compare and order rational numbers 73
Compare each pair by writing both values as percents rounded to the nearest tenth of a percent. Then write \(<\), \(>\), or \(=\). a) \(\frac{5}{7} \quad \square \quad 0.72\) b) \(\frac{1}{9} \quad \square \quad 0.11\)

Hints

- Write both values in each pair in the same form. - Calculate enough decimal places to round the percent correctly. - Percent means “per hundred.”

Solution

1. For a), \(\frac{5}{7} = 0.714285\ldots = 71.4285\ldots\% \approx 71.4\%\). Also, \(0.72 = 72.0\%\). Since \(71.4\% < 72.0\%\), \(\frac{5}{7} < 0.72\). 2. For b), \(\frac{1}{9} = 0.111\ldots = 11.111\ldots\% \approx 11.1\%\). Also, \(0.11 = 11.0\%\). Since \(11.1\% > 11.0\%\), \(\frac{1}{9} > 0.11\).

Answer

a) \(\frac{5}{7} < 0.72\), because \(71.4\% < 72.0\%\) b) \(\frac{1}{9} > 0.11\), because \(11.1\% > 11.0\%\)
Compare and order rational numbers 74
Order the following values from least to greatest. Write each one as a percent, rounding to the nearest tenth of a percent when needed. \(0.62, \frac{5}{8}, 62.8\%, \frac{11}{18}\)

Hints

- Write all the values in the same form before comparing them. - Convert the fractions and decimal to percents. - Compare the tenths digits of the percent values carefully.

Solution

1. Convert each value to a percent: \(0.62 = 62.0\%\), \(\frac{5}{8} = 0.625 = 62.5\%\), \(62.8\%\) is already a percent, and \(\frac{11}{18} = 0.6111\ldots = 61.111\ldots\% \approx 61.1\%\). 2. Compare the percents: \(61.1\% < 62.0\% < 62.5\% < 62.8\%\). 3. Replace the percents with the original values: \(\frac{11}{18} < 0.62 < \frac{5}{8} < 62.8\%\).

Answer

\(\frac{11}{18} < 0.62 < \frac{5}{8} < 62.8\%\)
Compare and order rational numbers 75
Order the quantities from least to greatest. Also write each quantity as a percent. A: Three out of five hundred B: One out of every four C: Twelve out of eighty D: \(0.007\)

Hints

- Convert every quantity to the same form, such as percent. - Write verbal portions as fractions first. - Simplify fractions before converting them.

Solution

1. Quantity A is \(\frac{3}{500} = 0.006 = 0.6\%\). 2. Quantity B is \(\frac{1}{4} = 0.25 = 25\%\). 3. Quantity C is \(\frac{12}{80} = \frac{3}{20} = 0.15 = 15\%\). 4. Quantity D is \(0.007 = 0.7\%\). 5. Therefore, \(0.6\% < 0.7\% < 15\% < 25\%\), so the order is A, D, C, B.

Answer

A \((0.6\%)\) < D \((0.7\%)\) < C \((15\%)\) < B \((25\%)\)
Compare and order rational numbers 76
Compare each pair. Write \(<\), \(>\), or \(=\). Convert the fractions and decimals to percents. a) \(\frac{3}{8}\) \(\square\) \(37\%\) b) \(0.06\) \(\square\) \(\frac{6}{100}\) c) \(\frac{2}{3}\) \(\square\) \(66\%\) d) \(0.125\) \(\square\) \(\frac{1}{8}\)

Hints

- Put both values in each pair into the requested percent form. - For repeating values, keep enough digits to decide the comparison. - Check whether the two percent values are less than, greater than, or equal to one another.

Solution

1. For a), \(\frac{3}{8} = 0.375 = 37.5\%\). Since \(37.5\% > 37\%\), \(\frac{3}{8} > 37\%\). 2. For b), \(0.06 = 6\%\) and \(\frac{6}{100} = 6\%\). Therefore, \(0.06 = \frac{6}{100}\). 3. For c), \(\frac{2}{3} = 0.666\ldots = 66.666\ldots\%\). Since \(66.666\ldots\% > 66\%\), \(\frac{2}{3} > 66\%\). 4. For d), \(0.125 = 12.5\%\) and \(\frac{1}{8} = 0.125 = 12.5\%\). Therefore, \(0.125 = \frac{1}{8}\).

Answer

a) \(\frac{3}{8} > 37\%\) b) \(0.06 = \frac{6}{100}\) c) \(\frac{2}{3} > 66\%\) d) \(0.125 = \frac{1}{8}\)
Compare and order rational numbers 77
Two sixth-grade classes compare results from a reading challenge. In Class 6A, \(\frac{13}{18}\) of the students earned a certificate. In Class 6B, \(72\%\) of the students earned a certificate. Which class had the greater proportion of students earn a certificate? Convert the fraction for Class 6A to a percent rounded to the nearest tenth of a percent.

Hints

- Write both proportions in the same form before comparing them. - Divide the numerator by the denominator, then convert the decimal to a percent.

Solution

1. Convert the fraction to a decimal: \(13\div18=0.7\overline{2}\). 2. Convert the decimal to a percent: \(0.7\overline{2}\times100\%\approx72.2\%\). 3. Since \(72.2\%>72\%\), Class 6A had the greater proportion.

Answer

Class 6A had the greater proportion because \(\frac{13}{18}\approx72.2\%\), which is greater than \(72\%\).
Compare and order rational numbers 78
A monitoring station records water levels in meters relative to a reference level: \(A = 0.75\), \(B = -\frac{4}{5}\), \(C = 0.8\), \(D = -\frac{3}{4}\), and \(E = -0.7\). Order the values from least to greatest using \(<\).

Hints

- Convert the fractions to decimals. - For negative numbers, the value with greater absolute value is smaller. - A number line can help organize the values.

Solution

1. Convert the fractions: \(B = -\frac{4}{5} = -0.8\) and \(D = -\frac{3}{4} = -0.75\). 2. Order the negative values: \(-0.8 < -0.75 < -0.7\). 3. Order the positive values: \(0.75 < 0.8\). 4. Therefore, \(B < D < E < A < C\).

Answer

\(B < D < E < A < C\)
Compare and order rational numbers 79
Let \(\frac{4}{7}\), \(0.62\), \(\frac{5}{8}\), and \(0.63\) be given. a) Order the numbers from least to greatest. b) Give a decimal with three decimal places that lies between \(0.62\) and \(\frac{5}{8}\).

Hints

- Convert each fraction to a decimal with enough places to compare. - Write \(0.62\) as \(0.620\) when looking for a number with three decimal places. - Check that your number is strictly between the two endpoints.

Solution

1. Convert the fractions to decimals: \(\frac{4}{7}\approx0.571\) and \(\frac{5}{8}=0.625\). 2. Therefore, \(\frac{4}{7}<0.62<\frac{5}{8}<0.63\). 3. Since \(0.62=0.620\), any of \(0.621\), \(0.622\), \(0.623\), or \(0.624\) lies between \(0.620\) and \(0.625\).

Answer

a) \(\frac{4}{7}<0.62<\frac{5}{8}<0.63\) b) One possible answer is \(0.621\).
Compare and order rational numbers 80
Four trails have these lengths: Trail A: \(7\frac{1}{2}\,\text{mi}\) Trail B: \(7.45\,\text{mi}\) Trail C: \(7\frac{3}{5}\,\text{mi}\) Trail D: \(7.505\,\text{mi}\) Order the trails from longest to shortest.

Hints

- Convert the mixed numbers to decimals. - Write all decimals with the same number of decimal places by adding trailing zeros. - The problem asks for descending order.

Solution

1. Convert the mixed numbers to decimals: Trail A is \(7.5\,\text{mi}\), and Trail C is \(7.6\,\text{mi}\). 2. Compare the four values: \(7.6>7.505>7.5>7.45\). 3. Therefore, the order from longest to shortest is Trail C, Trail D, Trail A, Trail B.

Answer

Trail C, Trail D, Trail A, Trail B
Compare and order rational numbers 81
Which digits from \(0\) through \(9\) can replace \(\square\) to make each statement true? List every possible digit. a) \(-4.1\square>-4.15\) b) \(-0.\square7<-0.4\) c) \(-8.2<-8.\square1\)

Hints

- First compare the corresponding positive magnitudes. - Remember that among negative numbers, the number with the greater magnitude is smaller. - Add trailing zeros when helpful so the decimal places line up.

Solution

1. For part a), \(-4.1\square>-4.15\) means the positive value \(4.1\square\) must be less than \(4.15\). The possible hundredths digits are \(0,1,2,3,4\). 2. For part b), write \(-0.4\) as \(-0.40\). For \(-0.\square7<-0.40\), the positive value \(0.\square7\) must be greater than \(0.40\). This happens for \(\square=4,5,6,7,8,9\). 3. For part c), write \(-8.2\) as \(-8.20\). The inequality requires \(8.20>8.\square1\), which is true only when \(\square=0\) or \(\square=1\).

Answer

a) \(\square\in\{0,1,2,3,4\}\) b) \(\square\in\{4,5,6,7,8,9\}\) c) \(\square\in\{0,1\}\)
Compare and order rational numbers 82
Consider \(-1.6\), \(-\frac{7}{4}\), \(-1.705\), and \(-\frac{3}{2}\). a) Order the numbers from least to greatest using \(<\). b) Give a rational number between the two greatest values in your ordered list.

Hints

- Convert the fractions to decimals so the representations match. - Order the values as they would appear from left to right on a number line. - For part b, use the size of the gap between the two greatest values.

Solution

1. Convert the fractions: \(-\frac{7}{4}=-1.75\) and \(-\frac{3}{2}=-1.5\). 2. Compare the values: \(-1.75<-1.705<-1.6<-1.5\). 3. Therefore, \(-\frac{7}{4}<-1.705<-1.6<-\frac{3}{2}\). 4. The two greatest values are \(-1.6\) and \(-1.5\), which are \(0.1\) unit apart. Half of that gap is \(0.05\), so \(-1.55\) is exactly halfway between them.

Answer

a) \(-\frac{7}{4}<-1.705<-1.6<-\frac{3}{2}\) b) Answers will vary. One possible answer is \(-1.55\).
Compare and order rational numbers 83
In the compound inequality below, \(k\) represents a digit from \(0\) through \(9\): \(-k.6<-3.4<-k.2\) Find every possible value of \(k\).

Hints

- Picture all three negative decimals on a number line. - Use the first inequality to decide which digits could place \(-k.6\) left of \(-3.4\). - Use the second inequality to decide which digits could place \(-k.2\) right of \(-3.4\).

Solution

1. For \(-k.6\) to be less than \(-3.4\), the number \(-k.6\) must lie to the left of \(-3.4\). This requires \(k\ge 3\); when \(k=3\), \(-3.6<-3.4\). 2. For \(-3.4\) to be less than \(-k.2\), the number \(-k.2\) must lie to the right of \(-3.4\). This requires \(k\le 3\); when \(k=3\), \(-3.4<-3.2\). 3. Both conditions hold only when \(k=3\). 4. Substitution gives \(-3.6<-3.4<-3.2\), which is true.

Answer

The only possible digit is \(k=3\).
Compare and order rational numbers 84
Let \(a = -1.2\), \(b = -\frac{5}{4}\), and \(c = -1.15\). Order these three numbers and their opposites \(-a\), \(-b\), and \(-c\) from least to greatest in one inequality chain.

Hints

- Find the opposite of each negative number. - Convert the fraction to a decimal. - Order the negative and positive values separately. - Reversing every sign reverses the order.

Solution

1. Convert \(b\): \(b = -\frac{5}{4} = -1.25\). 2. The opposites are \(-a = 1.2\), \(-b = 1.25\), and \(-c = 1.15\). 3. Order the negative values: \(-1.25 < -1.2 < -1.15\), so \(b < a < c\). 4. Order the positive values: \(1.15 < 1.2 < 1.25\), so \(-c < -a < -b\). 5. Combining them gives \(b < a < c < -c < -a < -b\).

Answer

\(b < a < c < -c < -a < -b\)
Compare and order rational numbers 85
Tim says, “The fraction \(\frac{1}{6}\) is exactly equal to \(16\%\).” Is Tim's statement correct? Justify your answer mathematically and state which value is greater.

Hints

- Express the fraction and the claimed percent in a common form. - Pay attention to whether the fraction's decimal representation terminates or repeats. - Use the resulting values to decide both equality and order.

Solution

1. Write the fraction as a decimal: \(1 \div 6 = 0.1666\ldots = 0.1\overline{6}\). 2. Convert the decimal to a percent: \(0.1\overline{6} = 16.\overline{6}\%\). 3. Since \(16.\overline{6}\%\) is not equal to \(16\%\), Tim's statement is incorrect. 4. Because \(16.\overline{6} > 16\), it follows that \(\frac{1}{6} > 16\%\).

Answer

Tim's statement is incorrect. \(\frac{1}{6} = 16.\overline{6}\% \approx 16.67\%\), which is greater than \(16\%\). Therefore, \(\frac{1}{6} > 16\%\).
Compare and order rational numbers 86
Compare each pair. Replace the blank with \(<\), \(>\), or \(=\). Justify each answer by rewriting both values in the same form. a) \(\frac{2}{5}\quad\square\quad0.38\) b) \(0.12\quad\square\quad\frac{3}{25}\) c) \(15\%\quad\square\quad\frac{1}{6}\) d) \(\frac{7}{8}\quad\square\quad0.87\)

Hints

- Choose a common form for each pair. - When comparing fractions, a common denominator may help. - Calculate enough decimal places to decide close comparisons.

Solution

1. \(\frac{2}{5}=0.4>0.38\), so a) is \(>\). 2. \(\frac{3}{25}=\frac{12}{100}=0.12\), so b) is \(=\). 3. \(15\%=\frac{9}{60}<\frac{10}{60}=\frac{1}{6}\), so c) is \(<\). 4. \(\frac{7}{8}=0.875>0.87\), so d) is \(>\).

Answer

a) \(>\), since \(\frac{2}{5}=0.40>0.38\). b) \(=\), since \(\frac{3}{25}=\frac{12}{100}=0.12\). c) \(<\), since \(15\%=\frac{9}{60}<\frac{10}{60}=\frac{1}{6}\). d) \(>\), since \(\frac{7}{8}=0.875>0.870\).
Compare and order rational numbers 87
Four values are given: \(A = \frac{4}{5}\), \(B = 0.75\), \(C = 82\%\), and \(D = \frac{17}{20}\). a) Order the values from least to greatest using \(<\). b) Find the difference between the greatest and least values. Write the result as both a decimal and a fraction in simplest form.

Hints

- Rewrite all four values in one common form, such as decimals. - Identify the greatest and least values before subtracting. - A difference is found by subtraction.

Solution

1. Rewrite each value as a decimal: \(A = \frac{4}{5} = 0.80\) \(B = 0.75\) \(C = 82\% = 0.82\) \(D = \frac{17}{20} = \frac{85}{100} = 0.85\) 2. Since \(0.75 < 0.80 < 0.82 < 0.85\), the order is \(B < A < C < D\). 3. The difference between the greatest and least values is \(0.85 - 0.75 = 0.10\). 4. As a fraction, \(0.10 = \frac{10}{100} = \frac{1}{10}\).

Answer

a) \(B < A < C < D\) b) Decimal: \(0.10\); fraction: \(\frac{1}{10}\)
Compare and order rational numbers 88
Use the four numbers \(-10,5,-2,0\). Write every possible true inequality chain that uses exactly three of the numbers and includes \(0\). Use \(<\) in each chain.

Hints

- First list every group of three that includes zero. - For each group, identify the least, middle, and greatest values. - The number of negative values determines whether zero is last or in the middle.

Solution

1. The three-number selections that include zero are \(\{-10,-2,0\}\), \(\{-10,5,0\}\), and \(\{-2,5,0\}\). 2. Ordering each selection gives \(-10<-2<0\), \(-10<0<5\), and \(-2<0<5\).

Answer

\(-10<-2<0\) \(-10<0<5\) \(-2<0<5\)
Compare and order rational numbers 89
Four cities recorded these morning temperatures: City A: \(-11\,^\circ\text{F}\) City B: \(-14\,^\circ\text{F}\) City C: \(2\,^\circ\text{F}\) City D: \(-3\,^\circ\text{F}\) a) List the cities from coldest to warmest. b) City E is warmer than City B but colder than City A. Give one possible integer temperature for City E. c) Write the opposite of City B’s temperature value.

Hints

- Colder temperatures are farther left on a number line. - List the integers strictly between \(-14\) and \(-11\). - Opposites have equal absolute values and different signs.

Solution

1. Ordering the temperatures gives \(-14<-11<-3<2\), so the cities from coldest to warmest are B, A, D, C. 2. An integer strictly between \(-14\) and \(-11\) can be \(-13\) or \(-12\). Either is a possible temperature for City E. 3. The opposite of \(-14\) is \(14\).

Answer

a) City B, City A, City D, City C b) One possible answer is \(-13\,^\circ\text{F}\) or \(-12\,^\circ\text{F}\). c) \(14\)
Compare and order rational numbers 90
Let these five numbers be given: \(\frac{7}{8}\), \(0.87\), \(\frac{4}{5}\), \(0.88\), \(\frac{17}{20}\) a) Order the numbers from least to greatest using \(<\). b) Which number is closest to \(0.9\)? Find the difference.

Hints

- Convert each fraction to a decimal. - Write all decimals with the same number of places when comparing. - Find the distance from \(0.9\) by subtraction.

Solution

1. Convert the fractions to decimals: \(\frac{7}{8}=0.875\), \(\frac{4}{5}=0.8\), and \(\frac{17}{20}=0.85\). 2. Order the values: \(0.8<0.85<0.87<0.875<0.88\). 3. Therefore, \(\frac{4}{5}<\frac{17}{20}<0.87<\frac{7}{8}<0.88\). 4. The closest value to \(0.9\) is \(0.88\), and the difference is \(0.9-0.88=0.02\).

Answer

a) \(\frac{4}{5}<\frac{17}{20}<0.87<\frac{7}{8}<0.88\) b) \(0.88\), with a difference of \(0.02\)
Compare and order rational numbers 91
An airplane is scheduled to cruise at \(10{,}000\,\text{ft}\). Three altitude checks give these readings: Check 1: \(10{,}200\,\text{ft}\) Check 2: \(9750\,\text{ft}\) Check 3: \(9900\,\text{ft}\) a) Write each deviation from the scheduled altitude as an integer. b) Order the three deviations from least to greatest using \(<\).

Hints

- Compare each measured altitude with the scheduled altitude. - Use a positive integer for an altitude above the target and a negative integer for one below it. - Picture the deviations on a number line before ordering them.

Solution

1. Check 1 is \(200\,\text{ft}\) above the scheduled altitude, so its deviation is \(+200\,\text{ft}\). 2. Check 2 is \(250\,\text{ft}\) below the scheduled altitude, so its deviation is \(-250\,\text{ft}\). 3. Check 3 is \(100\,\text{ft}\) below the scheduled altitude, so its deviation is \(-100\,\text{ft}\). 4. From least to greatest, \(-250<-100<+200\).

Answer

a) Check 1: \(+200\,\text{ft}\); Check 2: \(-250\,\text{ft}\); Check 3: \(-100\,\text{ft}\) b) \(-250<-100<+200\)
Compare and order rational numbers 92
Insert \(<\) or \(>\) between each pair. 1) \(-\frac{5}{9}\) and \(-\frac{7}{12}\) 2) \(-3.101\) and \(-3.11\) 3) \(-\frac{19}{20}\) and \(-0.9\) 4) \(-1\frac{2}{3}\) and \(-\frac{13}{8}\)

Hints

- Use common denominators for fraction pairs. - Add trailing zeros to compare decimals. - Convert between fractions and decimals when useful. - For negative numbers, smaller absolute value means a greater number.

Solution

1. Use denominator \(36\): \(-\frac{5}{9} = -\frac{20}{36}\) and \(-\frac{7}{12} = -\frac{21}{36}\). Since \(-20 > -21\), \(-\frac{5}{9} > -\frac{7}{12}\). 2. Write \(-3.11\) as \(-3.110\). Since \(-3.101\) is closer to zero, \(-3.101 > -3.11\). 3. Convert \(-\frac{19}{20} = -0.95\). Therefore, \(-\frac{19}{20} < -0.9\). 4. Convert to fractions with denominator \(24\): \(-1\frac{2}{3} = -\frac{5}{3} = -\frac{40}{24}\), and \(-\frac{13}{8} = -\frac{39}{24}\). Thus, \(-1\frac{2}{3} < -\frac{13}{8}\).

Answer

1) \(-\frac{5}{9} > -\frac{7}{12}\) 2) \(-3.101 > -3.11\) 3) \(-\frac{19}{20} < -0.9\) 4) \(-1\frac{2}{3} < -\frac{13}{8}\)
Compare and order rational numbers 93
Order the rational numbers from greatest to least: \(-3.05\), \(-\frac{13}{4}\), \(3.25\), \(3\frac{1}{5}\), \(-3.1\), \(0\), \(-0.03\)

Hints

- Separate the values into positive numbers, zero, and negative numbers. - Convert the fraction and mixed number to decimals. - For negative values, the one closer to zero is greater.

Solution

1. Convert the fraction and mixed number: \(-\frac{13}{4} = -3.25\) and \(3\frac{1}{5} = 3.2\). 2. Order the positive values: \(3.25 > 3.2\). 3. Zero is less than every positive value and greater than every negative value. 4. Order the negative values: \(-0.03 > -3.05 > -3.1 > -3.25\). 5. Therefore, \(3.25 > 3\frac{1}{5} > 0 > -0.03 > -3.05 > -3.1 > -\frac{13}{4}\).

Answer

\(3.25 > 3\frac{1}{5} > 0 > -0.03 > -3.05 > -3.1 > -\frac{13}{4}\)
Compare and order rational numbers 94
Order the numbers from least to greatest using \(<\): \(-\frac{1}{2}\), \(-0.45\), \(-\frac{3}{5}\), \(-0.55\), \(-0.4\)

Hints

- Convert the fractions to decimals. - Think of the values as temperatures on a thermometer. - Use the original forms in the final inequality. - Add trailing zeros if that helps align decimal places.

Solution

1. Convert the fractions: \(-\frac{1}{2} = -0.5\) and \(-\frac{3}{5} = -0.6\). 2. Compare the decimal values \(-0.5\), \(-0.45\), \(-0.6\), \(-0.55\), and \(-0.4\). 3. From least to greatest, \(-0.6 < -0.55 < -0.5 < -0.45 < -0.4\). 4. Using the original forms, \(-\frac{3}{5} < -0.55 < -\frac{1}{2} < -0.45 < -0.4\).

Answer

\(-\frac{3}{5} < -0.55 < -\frac{1}{2} < -0.45 < -0.4\)
Compare and order rational numbers 95
Consider \(-4.2\), \(-\frac{1}{2}\), \(-0.75\), \(-5\), \(-\frac{9}{4}\), and \(-0.1\). a) Which numbers are less than \(-1\)? b) Which numbers satisfy \(-3 < x < -0.5\)? c) Give another rational number that is less than every number in the list.

Hints

- Convert the fractions to decimals. - Use a number line to decide which values lie farther left. - For part b), check both strict inequalities. - Find the least listed value before choosing an even smaller number.

Solution

1. Convert the fractions: \(-\frac{1}{2} = -0.5\) and \(-\frac{9}{4} = -2.25\). 2. The numbers less than \(-1\) are \(-4.2\), \(-5\), and \(-\frac{9}{4}\). 3. The values strictly between \(-3\) and \(-0.5\) are \(-0.75\) and \(-\frac{9}{4}\). The endpoint \(-\frac{1}{2} = -0.5\) is not included. 4. The least listed value is \(-5\). Any rational number less than \(-5\), such as \(-6\), answers part c).

Answer

a) \(-4.2\), \(-5\), and \(-\frac{9}{4}\) b) \(-0.75\) and \(-\frac{9}{4}\) c) Answers will vary. One example is \(-6\).
Compare and order rational numbers 96
A diver is at \(-12.5\,\text{m}\) relative to sea level. a) Give two numbers that represent positions deeper than the diver. b) A fish is at a position greater than \(-12.5\) but less than \(-10\). Give one possible decimal and one possible fraction for its position. c) Compare \(-12.5\) and \(-13\). Which is less? Briefly explain using the number line.

Hints

- Deeper positions are farther below zero. - Values farther left on the number line are smaller. - For part b), choose values strictly inside the interval.

Solution

1. Deeper positions correspond to smaller numbers. Two examples less than \(-12.5\) are \(-13\) and \(-15\). 2. A valid position must satisfy \(-12.5 < y < -10\). One decimal example is \(-11.5\), and one fraction example is \(-\frac{21}{2} = -10.5\). 3. Since \(-13\) lies to the left of \(-12.5\), \(-13 < -12.5\).

Answer

a) Answers will vary. One possible pair is \(-13\) and \(-15\). b) Answers will vary. One decimal is \(-11.5\), and one fraction is \(-\frac{21}{2}\). c) \(-13\) is less than \(-12.5\).
Compare and order rational numbers 97
A weather station recorded these temperatures at midnight during one week: Monday: \(-4\,^\circ\text{C}\), Tuesday: \(-1\,^\circ\text{C}\), Wednesday: \(3\,^\circ\text{C}\), Thursday: \(5\,^\circ\text{C}\), Friday: \(-2\,^\circ\text{C}\), Saturday: \(-6\,^\circ\text{C}\), Sunday: \(0\,^\circ\text{C}\). a) Find the highest and lowest temperatures. b) Find the difference between the warmest and coldest temperatures. c) List the days from coldest to warmest.

Hints

- Compare the temperatures by placing them on a number line. - Count the distance from the coldest reading to zero, then from zero to the warmest reading. - Order negative temperatures carefully: a value farther below zero is colder.

Solution

1. The lowest temperature is \(-6\,^\circ\text{C}\) on Saturday, and the highest is \(5\,^\circ\text{C}\) on Thursday. 2. On a number line, the trip from \(-6\) to \(0\) is \(6\) units, and from \(0\) to \(5\) is \(5\) units. Together the temperatures are \(11\,^{\circ}\text{C}\) apart. 3. Ordering the temperatures gives Saturday, Monday, Friday, Tuesday, Sunday, Wednesday, Thursday.

Answer

a) Highest: \(5\,^\circ\text{C}\); lowest: \(-6\,^\circ\text{C}\) b) \(11\,^\circ\text{C}\) c) Saturday, Monday, Friday, Tuesday, Sunday, Wednesday, Thursday
Compare and order rational numbers 98
The number line shows the \(7\) fractions with denominator \(4\) that lie strictly between \(10\) and \(12\). a) What values are marked by \(A\) and \(B\)? Write them as mixed numbers. b) How many fractions with denominator \(250\) lie strictly between \(10\) and \(12\)? Explain your reasoning.
Figure for problem 535302

Hints

- Read the marked points in fourths. - For part b), determine how many \(\frac{1}{250}\)-length intervals fit in a span of \(2\). - Do not count the two endpoints.

Solution

1. The number line is divided into fourths. Point \(A\) is three fourths past \(10\), so \(A=10\frac{3}{4}\). Point \(B\) is two fourths past \(11\), so \(B=11\frac{2}{4}=11\frac{1}{2}\). 2. The interval from \(10\) to \(12\) has length \(2\). Dividing each whole into \(250\) equal parts creates \(2\times250=500\) equal intervals. 3. The interior tick marks are one fewer than the number of intervals, so there are \(500-1=499\) fractions with denominator \(250\) strictly between the endpoints.

Answer

a) \(A=10\frac{3}{4}\), \(B=11\frac{1}{2}\) b) \(499\) fractions
Compare and order rational numbers 99
Find all fractions with denominator \(24\) strictly between \(\frac{1}{3}\) and \(\frac{1}{2}\). List them in increasing order and explain why your list is complete.

Hints

- How many twenty-fourths are in one third? - Think about which numerators would keep a fraction inside the interval. - Check whether any two numerators in your list have another whole number between them.

Solution

1. Write the bounds in twenty-fourths: \(\frac{1}{3}=\frac{8}{24}\) and \(\frac{1}{2}=\frac{12}{24}\). 2. The integer numerators strictly between \(8\) and \(12\) are \(9,10,11\). 3. The required fractions are \(\frac{9}{24}<\frac{10}{24}<\frac{11}{24}\); no other integer numerator fits.

Answer

\(\frac{9}{24}<\frac{10}{24}<\frac{11}{24}\). The endpoints are \(\frac{8}{24}\) and \(\frac{12}{24}\); the only whole numerators strictly between \(8\) and \(12\) are \(9,10,11\).
Compare and order rational numbers 100
Eli makes a fraction from \(\frac{1}{2}\) and \(\frac{3}{4}\) by adding the numerators and adding the denominators. a) What fraction does Eli get? b) Is the new fraction between the two starting fractions? c) Is it exactly halfway between them? Show how you know.

Hints

- Think about how to compare fractions with different denominators. - For the halfway question, compare the gaps on both sides of the new fraction. - Use exact fractions rather than rounded decimals to check those gaps.

Solution

1. Eli gets \(\frac{1+3}{2+4}=\frac{4}{6}=\frac{2}{3}\). 2. With denominator 12, \(\frac{1}{2}=\frac{6}{12}\), \(\frac{2}{3}=\frac{8}{12}\), and \(\frac{3}{4}=\frac{9}{12}\). So the new fraction is between the starting fractions. 3. Its distance from \(\frac{1}{2}\) is \(\frac{2}{12}=\frac{1}{6}\), while its distance from \(\frac{3}{4}\) is \(\frac{1}{12}\). These distances differ, so it is not halfway between them.

Answer

a) \(\frac{4}{6}=\frac{2}{3}\) b) Yes, because \(\frac{1}{2}=\frac{6}{12}<\frac{8}{12}=\frac{2}{3}<\frac{9}{12}=\frac{3}{4}\). c) No. The distances to the endpoints are \(\frac{1}{6}\) and \(\frac{1}{12}\), which are not equal.
Compare and order rational numbers 101
Start with \(\frac{7}{20}\) and \(\frac{2}{5}\). a) Find the fraction halfway between them. b) Find the fraction halfway between your answer to a) and \(\frac{2}{5}\). c) Explain how you could keep finding new fractions between the two starting numbers without stopping.

Hints

- Rewrite the two starting fractions with a common denominator. - Check a proposed halfway value by comparing its distance from the two ends. - What can you say about the sizes of the gaps created in a) and b)?

Solution

1. Since \(\frac{2}{5}=\frac{8}{20}\), the first midpoint is \(\left(\frac{7}{20}+\frac{8}{20}\right)\div2=\frac{15}{40}=\frac{3}{8}\). 2. Rewrite \(\frac{3}{8}=\frac{30}{80}\) and \(\frac{2}{5}=\frac{32}{80}\). Their midpoint is \(\frac{31}{80}\). 3. The midpoint of two different fractions is always strictly between them. Repeating between the latest midpoint and \(\frac{2}{5}\) gives a different fraction each time.

Answer

a) \(\frac{3}{8}\), halfway between \(\frac{7}{20}\) and \(\frac{8}{20}\). b) \(\frac{31}{80}\), halfway between \(\frac{30}{80}\) and \(\frac{32}{80}\). c) Keep finding the midpoint between the latest fraction and \(\frac{2}{5}\). The endpoints are still different, so each midpoint gives another fraction strictly between the original two.
Compare and order rational numbers 102
Order these fractions from least to greatest. First find the least common multiple of all four denominators. \(\frac{13}{18}\), \(\frac{19}{24}\), \(\frac{25}{36}\), \(\frac{11}{12}\)

Hints

- Find a number divisible by all four denominators. - Rewrite each fraction with that common denominator. - Match each new numerator to its original fraction before ordering.

Solution

1. The least common multiple of \(18\), \(24\), \(36\), and \(12\) is \(72\). 2. Rewrite each fraction: \(\frac{13}{18}=\frac{52}{72}\), \(\frac{19}{24}=\frac{57}{72}\), \(\frac{25}{36}=\frac{50}{72}\), and \(\frac{11}{12}=\frac{66}{72}\). 3. Since \(50<52<57<66\), the order is \(\frac{25}{36}<\frac{13}{18}<\frac{19}{24}<\frac{11}{12}\).

Answer

\(\frac{25}{36}<\frac{13}{18}<\frac{19}{24}<\frac{11}{12}\)
Compare and order rational numbers 103
A fraction \(\frac{k}{n}\), where \(k\) and \(n\) are natural numbers, must lie strictly between \(\frac{1}{5}\) and \(\frac{1}{4}\). a) Find the smallest possible denominator \(n\) for which such a fraction exists. b) Give the corresponding fraction for that denominator.

Hints

- Because the denominator must be as small as possible, test denominators in increasing order. - For each denominator, check only the fractions closest to the interval between \(\frac{1}{5}\) and \(\frac{1}{4}\). - Stop when one fraction is strictly above the lower bound and strictly below the upper bound.

Solution

1. Test denominators from smallest to largest, because the question asks for the smallest possible denominator. 2. With denominators \(1\) through \(4\), every positive fraction is at least \(\frac{1}{4}\). With denominator \(5\), \(\frac{1}{5}\) is an endpoint and \(\frac{2}{5}>\frac{1}{4}\). 3. For denominators \(6\), \(7\), and \(8\), the first positive fractions above \(\frac{1}{5}\) are \(\frac{2}{6}\), \(\frac{2}{7}\), and \(\frac{2}{8}\); each is at least \(\frac{1}{4}\). 4. For denominator \(9\), \(\frac{2}{9}\) satisfies \(\frac{1}{5}<\frac{2}{9}<\frac{1}{4}\). Thus the smallest denominator is \(9\).

Answer

a) \(n=9\) b) \(\frac{2}{9}\)
Compare and order rational numbers 104
Let \(A=\frac{123}{124}\), \(B=\frac{124}{123}\), and \(C=\frac{124}{125}\). Order the fractions from least to greatest without finding common denominators or converting to decimals. Explain your reasoning.

Hints

- First identify which fractions are below \(1\) and which are above \(1\). - For fractions just below \(1\), compare the amount missing from \(1\). - A smaller missing amount gives a fraction closer to \(1\).

Solution

1. \(B=\frac{124}{123}>1\), while \(A\) and \(C\) are both less than \(1\). Therefore, \(B\) is greatest. 2. Write the other fractions by their distances from \(1\): \(A=1-\frac{1}{124}\) and \(C=1-\frac{1}{125}\). 3. Since \(\frac{1}{124}>\frac{1}{125}\), \(A\) is farther below \(1\) than \(C\). Thus, \(A<C<B\).

Answer

\(A<C<B\), or \(\frac{123}{124}<\frac{124}{125}<\frac{124}{123}\).
Compare and order rational numbers 105
Order \(\frac{7}{15}\), \(\frac{7}{13}\), and \(\frac{8}{15}\) from least to greatest. Justify your order by comparing numerators, denominators, and distances from \(\frac{1}{2}\), rather than finding one common denominator.

Hints

- Start with the pair that has equal denominators. - Then compare the pair that has equal numerators. - For the last comparison, determine how far each fraction is above \(\frac{1}{2}\).

Solution

1. Since \(\frac{7}{15}\) and \(\frac{8}{15}\) have the same denominator, \(\frac{7}{15}<\frac{8}{15}\). 2. Since \(\frac{7}{15}\) and \(\frac{7}{13}\) have the same numerator, the fraction with the larger denominator is smaller. Thus, \(\frac{7}{15}<\frac{7}{13}\). 3. Compare the remaining pair with \(\frac{1}{2}\): \(\frac{8}{15}=\frac{1}{2}+\frac{1}{30}\) and \(\frac{7}{13}=\frac{1}{2}+\frac{1}{26}\). Since \(\frac{1}{26}>\frac{1}{30}\), \(\frac{7}{13}>\frac{8}{15}\). 4. Therefore, \(\frac{7}{15}<\frac{8}{15}<\frac{7}{13}\).

Answer

\(\frac{7}{15}<\frac{8}{15}<\frac{7}{13}\)
Compare and order rational numbers 106
Eszter says, “There are fewer fractions between \(\frac{1}{100}\) and \(\frac{2}{100}\) than between \(\frac{1}{10}\) and \(\frac{2}{10}\), because the first interval is much shorter on a number line.” Is Eszter correct? Explain using a property of fractions.

Hints

- Ask whether fractions have immediate neighbors on a number line. - Rewrite the endpoints with a much larger common denominator. - Consider whether the denominator can keep increasing.

Solution

1. Eszter is not correct. 2. Between any two different rational numbers, there are infinitely many other rational numbers. 3. For example, \(\frac{1}{100}=\frac{10}{1000}\) and \(\frac{2}{100}=\frac{20}{1000}\), so fractions such as \(\frac{11}{1000}\), \(\frac{12}{1000}\), and many others lie between them. Rewriting with still larger denominators produces more fractions, and this process can continue without end.

Answer

Eszter is not correct. Infinitely many fractions lie between any two different fractions, no matter how close the endpoints are.
Compare and order rational numbers 107
Let \(A=\frac{5}{8}\) and \(B=\frac{6}{8}\). a) Find the fraction \(M_1\) halfway between \(A\) and \(B\). b) Find the fraction \(M_2\) halfway between \(A\) and \(M_1\). c) Put \(A\), \(M_2\), \(M_1\), and \(B\) in order. Explain how you could keep finding new fractions between \(A\) and \(B\).

Hints

- How can you find the number halfway between two positive fractions? - Use \(A\) and your first answer as the next two endpoints. - Compare all four values using a common denominator. Could you repeat the same step again?

Solution

1. Halfway between the endpoints is \(M_1=\left(\frac{5}{8}+\frac{6}{8}\right)\div2=\frac{11}{16}\). 2. Since \(A=\frac{10}{16}\), the next midpoint is \(M_2=\left(\frac{10}{16}+\frac{11}{16}\right)\div2=\frac{21}{32}\). 3. In thirty-seconds, \(A=\frac{20}{32}\), \(M_2=\frac{21}{32}\), \(M_1=\frac{22}{32}\), and \(B=\frac{24}{32}\). Therefore \(A<M_2<M_1<B\). 4. Repeating the midpoint step between \(A\) and the newest point always gives a fraction strictly between them, so each step gives another different fraction in the original interval.

Answer

a) \(M_1=\frac{11}{16}\) b) \(M_2=\frac{21}{32}\) c) \(\frac{5}{8}<\frac{21}{32}<\frac{11}{16}<\frac{6}{8}\). Each new midpoint lies between \(A\) and the previous one, so the process gives different fractions and can continue.
Compare and order rational numbers 108
Consider all fractions with denominator \(20\) that are greater than \(\frac{2}{5}\) and less than \(\frac{4}{5}\). Which of these fractions are already in simplest form?

Hints

- Rewrite both boundary fractions with denominator \(20\). - List the possible integer numerators strictly between the two boundary numerators. - Check which numerators share no factor of \(2\) or \(5\) with \(20\).

Solution

1. Rewrite the boundaries with denominator \(20\): \(\frac{2}{5}=\frac{8}{20}\) and \(\frac{4}{5}=\frac{16}{20}\). 2. The fractions in the interval are \(\frac{9}{20}\), \(\frac{10}{20}\), \(\frac{11}{20}\), \(\frac{12}{20}\), \(\frac{13}{20}\), \(\frac{14}{20}\), and \(\frac{15}{20}\). 3. A fraction with denominator \(20\) is in simplest form when its numerator has no common factor with \(20\) other than \(1\). 4. The numerators \(9\), \(11\), and \(13\) are relatively prime to \(20\). Therefore, the fractions in simplest form are \(\frac{9}{20}\), \(\frac{11}{20}\), and \(\frac{13}{20}\).

Answer

\(\frac{9}{20}\), \(\frac{11}{20}\), and \(\frac{13}{20}\)
Compare and order rational numbers 109
Petr suggests this method for finding a fraction between two fractions: add the numerators for the new numerator and add the denominators for the new denominator. a) Apply the method to \(\frac{1}{4}\) and \(\frac{1}{2}\). What fraction do you get? b) Verify that the new fraction lies between \(\frac{1}{4}\) and \(\frac{1}{2}\). c) Is the new fraction exactly halfway between the original fractions? Compare it with their arithmetic mean.

Hints

- Apply Petr's proposed rule carefully and simplify the result. - To test whether the result lies between the endpoints, express the fractions in a directly comparable form. - For the halfway question, compare the proposed fraction with the midpoint of the two endpoint values.

Solution

1. Add the numerators and denominators: \(\frac{1+1}{4+2}=\frac{2}{6}=\frac{1}{3}\). 2. Using denominator \(12\), \(\frac{1}{4}=\frac{3}{12}\), \(\frac{1}{3}=\frac{4}{12}\), and \(\frac{1}{2}=\frac{6}{12}\). Thus, \(\frac{1}{4}<\frac{1}{3}<\frac{1}{2}\). 3. The arithmetic mean is \(\left(\frac{1}{4}+\frac{1}{2}\right)\div2=\frac{3}{4}\div2=\frac{3}{8}\). 4. Since \(\frac{1}{3}=\frac{8}{24}\) and \(\frac{3}{8}=\frac{9}{24}\), the new fraction is not exactly halfway between the original fractions.

Answer

a) \(\frac{1}{3}\) b) Yes, because \(\frac{1}{4}<\frac{1}{3}<\frac{1}{2}\). c) No. The exact midpoint is \(\frac{3}{8}\).

All problems may be used, copied and printed free of charge for school and tutoring, including paid tutoring. Commercial adaptations as well as publication or redistribution on the internet are not permitted.