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Add tenths and hundredths

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5406434
The two hundred grids represent \(\frac{6}{10}\) and \(\frac{7}{100}\). Find the sum. Write it as a fraction in hundredths and as a decimal.
Figure for problem 540643

Hints

- Use the grids to see how many hundredths each addend represents. - Rename the tenths as hundredths before adding. - Read the final number of hundredths as a decimal.

Solution

1. Rename \(\frac{6}{10}\) as \(\frac{60}{100}\). 2. Add: \(\frac{60}{100}+\frac{7}{100}=\frac{67}{100}\). 3. The decimal form of \(\frac{67}{100}\) is \(0.67\).

Answer

\(\frac{67}{100}=0.67\)
5406494
Complete the equation \(\frac{6}{10}+\frac{\square}{100}=1\).

Hints

- Express the whole and the tenths fraction in hundredths. - Find the gap between the known amount and one whole. - Use that gap as the missing numerator.

Solution

1. Rewrite \(\frac{6}{10}\) as \(\frac{60}{100}\) and \(1\) as \(\frac{100}{100}\). 2. The missing number of hundredths is \(100-60=40\). 3. Therefore, the missing fraction is \(\frac{40}{100}\).

Answer

\(40\)
5406524
Does reversing the addends change the value of \(\frac{2}{10}+\frac{59}{100}\)? Compare it with \(\frac{59}{100}+\frac{2}{10}\).

Hints

- Rewrite the tenths addend as hundredths in both expressions. - Compare the same two quantities in the two different orders. - Addition can be checked by evaluating each expression.

Solution

1. The first sum is \(\frac{20}{100}+\frac{59}{100}=\frac{79}{100}\). 2. The second sum is \(\frac{59}{100}+\frac{20}{100}=\frac{79}{100}\). 3. Reversing the addends does not change the sum.

Answer

No. Both sums equal \(\frac{79}{100}=0.79\).
5408124
Add \(\frac{6}{10}+\frac{40}{100}+\frac{17}{100}\). Choose a pair to combine first so that the intermediate result is exactly one whole, then finish the sum.

Hints

- Look for two addends whose hundredths numerators total \(100\). - Reorder the addends to make a whole number first. - Add the remaining fraction after forming the whole.

Solution

1. Rename \(\frac{6}{10}\) as \(\frac{60}{100}\). 2. Combine \(\frac{60}{100}+\frac{40}{100}=1\). 3. Then \(1+\frac{17}{100}=1\frac{17}{100}=1.17\).

Answer

Combine \(\frac{6}{10}=\frac{60}{100}\) with \(\frac{40}{100}\) first to make \(1\). The final sum is \(1.17\).
5408404
The \(10\times10\) grid represents one whole. Nine complete rows are shaded. More individual squares will be shaded until the total shaded amount is \(0.96\). a) Write the current shaded amount as a fraction in tenths and as a fraction in hundredths. b) How many additional small squares must be shaded? c) Write an addition equation for the completed grid.
Figure for problem 540840

Hints

- Relate each complete row to one tenth of the grid. - Express the target decimal as hundredths. - Find the difference between the current shaded hundredths and the target.

Solution

1. Nine complete rows represent \(\frac{9}{10}=\frac{90}{100}\). 2. The target is \(0.96=\frac{96}{100}\). 3. The additional amount is \(\frac{96}{100}-\frac{90}{100}=\frac{6}{100}\), so \(6\) more small squares must be shaded. 4. The completed equation is \(\frac{9}{10}+\frac{6}{100}=\frac{96}{100}=0.96\).

Answer

a) \(\frac{9}{10}=\frac{90}{100}\) b) \(6\) small squares c) \(\frac{9}{10}+\frac{6}{100}=\frac{96}{100}=0.96\)
5406444
The two hundred grids represent \(\frac{5}{10}\) and \(\frac{18}{100}\). Tessa writes \(\frac{5}{10}+\frac{18}{100}=\frac{23}{110}\). Explain the error and find the correct sum.
Figure for problem 540644

Hints

- Use the grids to compare the sizes of tenths and hundredths. - Rewrite the tenths fraction using hundredths before combining. - Denominators name the part size; they are not added in this situation.

Solution

1. The addends use different-sized parts, so first rename \(\frac{5}{10}=\frac{50}{100}\). 2. Add hundredths: \(\frac{50}{100}+\frac{18}{100}=\frac{68}{100}\). 3. Tessa incorrectly added the denominators instead of expressing both fractions with the same unit.

Answer

The correct sum is \(\frac{68}{100}=0.68\).
5406454
Find \(\frac{8}{10}+\frac{47}{100}\). Write the result as a fraction in hundredths, a mixed number, and a decimal.

Hints

- Convert the tenths to hundredths before adding. - Notice whether the total number of hundredths passes one hundred. - Separate one whole from the remaining hundredths.

Solution

1. Rename \(\frac{8}{10}\) as \(\frac{80}{100}\). 2. Add: \(\frac{80}{100}+\frac{47}{100}=\frac{127}{100}\). 3. The result is \(1\frac{27}{100}=1.27\).

Answer

\(\frac{127}{100}=1\frac{27}{100}=1.27\)
5406464
Jordan rewrites \(\frac{3}{10}\) as \(\frac{3}{100}\) and then adds \(\frac{19}{100}\). Explain what should be changed and find the correct sum.

Hints

- Think about how many hundredths are in one tenth. - Renaming a fraction must preserve its value. - Check whether the rewritten fraction is the same size as the original.

Solution

1. One tenth equals ten hundredths, so \(\frac{3}{10}=\frac{30}{100}\), not \(\frac{3}{100}\). 2. Add the correct hundredths: \(\frac{30}{100}+\frac{19}{100}=\frac{49}{100}\). 3. The correct decimal sum is \(0.49\).

Answer

Change \(\frac{3}{100}\) to \(\frac{30}{100}\). The sum is \(\frac{49}{100}=0.49\).
5406474
Compare \(\frac{2}{10}+\frac{34}{100}\) with \(\frac{1}{2}\). a) Is the sum less than, equal to, or greater than \(\frac{1}{2}\)? b) What is the exact difference?

Hints

- Express the sum and the benchmark using hundredths. - Compare the total number of hundredths with \(50\). - For part b), subtract the smaller value from the larger value.

Solution

1. Rename \(\frac{2}{10}\) as \(\frac{20}{100}\). 2. The sum is \(\frac{20}{100}+\frac{34}{100}=\frac{54}{100}\). 3. Since \(\frac{1}{2}=\frac{50}{100}\), the sum is greater than \(\frac{1}{2}\). 4. The difference is \(\frac{54}{100}-\frac{50}{100}=\frac{4}{100}\).

Answer

a) Greater than \(\frac{1}{2}\) b) \(\frac{4}{100}\)
5406484
The box in \(\frac{\square}{10}+\frac{7}{100}<\frac{1}{2}\) must contain a whole-number digit from \(0\) through \(9\). List every digit that makes the inequality true.

Hints

- Express \(\frac{1}{2}\) in hundredths. - Each possible tenths digit contributes a multiple of ten hundredths. - Find the first digit that makes the total reach or pass \(50\) hundredths. - Explain why every larger digit must also fail.

Solution

1. Rewrite the inequality in hundredths: \(\frac{10\square+7}{100}<\frac{50}{100}\). 2. The digits \(0\), \(1\), \(2\), \(3\), and \(4\) give totals of \(7\), \(17\), \(27\), \(37\), and \(47\) hundredths, all less than \(50\) hundredths. 3. The digit \(5\) gives \(57\) hundredths, which is too large. 4. Any digit greater than \(5\) gives an even larger total, so the complete list is \(0,1,2,3,4\).

Answer

\(0,1,2,3,4\)
5406504
Find \(\frac{2}{10}+\frac{3}{10}+\frac{14}{100}\). Write the result as a fraction in hundredths and as a decimal.

Hints

- Combine addends with the same denominator first. - Rename the tenths total as hundredths. - Add the final hundredths amount and write its decimal form.

Solution

1. Combine the tenths: \(\frac{2}{10}+\frac{3}{10}=\frac{5}{10}=\frac{50}{100}\). 2. Add the remaining hundredths: \(\frac{50}{100}+\frac{14}{100}=\frac{64}{100}\). 3. The decimal form is \(0.64\).

Answer

\(\frac{64}{100}=0.64\)
5406514
The marker represents \(\frac{6}{10}+\frac{17}{100}\). Between which two consecutive tenths does the sum lie?
Figure for problem 540651

Hints

- Find the exact sum in hundredths first. - Locate that hundredths value on the number line. - Identify the labeled tenths immediately below and above it.

Solution

1. Rename \(\frac{6}{10}\) as \(\frac{60}{100}\). 2. The sum is \(\frac{60}{100}+\frac{17}{100}=\frac{77}{100}=0.77\). 3. Since \(0.7<0.77<0.8\), the sum lies between seven tenths and eight tenths.

Answer

Between \(0.7\) and \(0.8\)
5406534
Compare \(\frac{3}{10}+\frac{42}{100}\) and \(\frac{5}{10}+\frac{19}{100}\). a) Which sum is greater? b) By how much?

Hints

- Evaluate both expressions in hundredths. - Compare the two totals before answering part a). - For part b), subtract the smaller total from the larger total.

Solution

1. The first sum is \(\frac{30}{100}+\frac{42}{100}=\frac{72}{100}\). 2. The second sum is \(\frac{50}{100}+\frac{19}{100}=\frac{69}{100}\). 3. Since \(\frac{72}{100}>\frac{69}{100}\), the first sum is greater. 4. The difference is \(\frac{72}{100}-\frac{69}{100}=\frac{3}{100}\).

Answer

a) \(\frac{3}{10}+\frac{42}{100}\) b) \(\frac{3}{100}\)
5406544
Omar says, “If both addends are less than \(1\), their sum must also be less than \(1\).” Use \(\frac{7}{10}+\frac{44}{100}\) to decide whether his statement is true.

Hints

- A single counterexample is enough to disprove an “always” statement. - Add the given fractions after expressing them in the same unit. - Compare the resulting number of hundredths with one hundred.

Solution

1. Rename \(\frac{7}{10}\) as \(\frac{70}{100}\). 2. The sum is \(\frac{70}{100}+\frac{44}{100}=\frac{114}{100}=1.14\). 3. Both addends are less than \(1\), but their sum is greater than \(1\), so Omar’s statement is false.

Answer

The statement is false because \(\frac{7}{10}+\frac{44}{100}=1.14\).
5406554
Use each card once to make two equal sums. Tenths cards: \(\frac{2}{10}\), \(\frac{4}{10}\). Hundredths cards: \(\frac{13}{100}\), \(\frac{33}{100}\). Pair one tenths card with one hundredths card in each sum.

Hints

- Convert each tenths card to hundredths. - Compare how much larger one tenths card is than the other. - Balance the larger tenths card with the smaller hundredths card.

Solution

1. Convert the tenths cards to hundredths: \(\frac{2}{10}=\frac{20}{100}\) and \(\frac{4}{10}=\frac{40}{100}\). 2. Pair \(\frac{20}{100}\) with \(\frac{33}{100}\) to get \(\frac{53}{100}\). 3. Pair \(\frac{40}{100}\) with \(\frac{13}{100}\) to get \(\frac{53}{100}\). 4. Therefore, the two sums are equal.

Answer

\(\frac{2}{10}+\frac{33}{100}=\frac{4}{10}+\frac{13}{100}=\frac{53}{100}\)
5406564
Ava writes \(\frac{2}{10}+\frac{47}{100}=0.247\) by placing the digits next to each other. Explain why this is not valid and find the correct sum.

Hints

- Addition combines values, not written digit strings. - Express both fractions as hundredths. - Use the total number of hundredths to write the decimal.

Solution

1. Rename \(\frac{2}{10}\) as \(\frac{20}{100}\). 2. Add the hundredths: \(\frac{20}{100}+\frac{47}{100}=\frac{67}{100}\). 3. The correct decimal is \(0.67\); joining digits does not combine place values correctly.

Answer

The correct sum is \(\frac{67}{100}=0.67\).
5406574
Order these sums from least to greatest: \(\frac{3}{10}+\frac{28}{100}\), \(\frac{4}{10}+\frac{23}{100}\), \(\frac{5}{10}+\frac{11}{100}\).

Hints

- Convert every tenths addend to hundredths. - Evaluate the three expressions before ordering them. - Compare the resulting numerators because the denominators match.

Solution

1. The first sum is \(\frac{30}{100}+\frac{28}{100}=\frac{58}{100}\). 2. The second sum is \(\frac{40}{100}+\frac{23}{100}=\frac{63}{100}\). 3. The third sum is \(\frac{50}{100}+\frac{11}{100}=\frac{61}{100}\). 4. Since \(58<61<63\), the order is first sum, third sum, second sum.

Answer

\(\frac{3}{10}+\frac{28}{100}<\frac{5}{10}+\frac{11}{100}<\frac{4}{10}+\frac{23}{100}\)
5406584
Two paper strips for a class mural measure \(\frac{7}{10}\,\text{m}\) and \(\frac{26}{100}\,\text{m}\). a) What is their combined length? b) How many hundredths of a meter short of \(1\,\text{m}\) is the combined length?

Hints

- For part a), combine the strip lengths using hundredths of a meter. - Express one meter in the same fractional unit. - For part b), subtract the combined length from one whole meter.

Solution

1. Rename \(\frac{7}{10}\) as \(\frac{70}{100}\). 2. The combined length is \(\frac{70}{100}+\frac{26}{100}=\frac{96}{100}=0.96\) meter. 3. One meter is \(\frac{100}{100}\) meter, so the gap is \(\frac{100}{100}-\frac{96}{100}=\frac{4}{100}\) meter.

Answer

a) \(0.96\,\text{m}\) b) \(\frac{4}{100}\,\text{m}\)
5406594
Kai rewrites \(\frac{5}{10}\) as \(\frac{500}{100}\) before adding \(\frac{8}{100}\). Explain why the rewrite is too large and find the correct sum.

Hints

- An equivalent fraction must keep the same value. - Compare the proposed rewrite with one whole. - Use the same scale factor for the numerator and denominator.

Solution

1. Multiplying the denominator by \(10\) requires multiplying the numerator by \(10\), so \(\frac{5}{10}=\frac{50}{100}\). 2. The fraction \(\frac{500}{100}=5\), which is not equal to \(\frac{5}{10}\). 3. The correct sum is \(\frac{50}{100}+\frac{8}{100}=\frac{58}{100}=0.58\).

Answer

The correct rewrite is \(\frac{50}{100}\), and the sum is \(0.58\).
5408004
A rain gauge already contains \(\frac{15}{100}\) inch of water. A storm adds \(\frac{4}{10}\) inch, and then \(\frac{8}{100}\) inch spills out. What amount remains? Record the change as one addition-subtraction expression.

Hints

- Distinguish the amount added from the amount removed. - Express every change in the same fractional unit. - Follow the events in chronological order.

Solution

1. Rename \(\frac{4}{10}\) as \(\frac{40}{100}\). 2. The amount is \(\frac{15}{100}+\frac{40}{100}-\frac{8}{100}=\frac{47}{100}\). 3. As a decimal, the amount is \(0.47\) inch.

Answer

\(\frac{15}{100}+\frac{40}{100}-\frac{8}{100}=\frac{47}{100}=0.47\) inch
5408014
Two tenths numerators \(a\) and \(b\) satisfy \(\frac{a}{10}+\frac{b}{10}+\frac{7}{100}=\frac{87}{100}\), and \(a\) is \(2\) greater than \(b\). Find both digits.

Hints

- Remove the known hundredths part from the target first. - Translate the remaining tenths into a condition on the two numerators. - Find two digits with the required sum and difference.

Solution

1. The two tenths addends must total \(\frac{80}{100}=\frac{8}{10}\), so \(a+b=8\). 2. The second condition gives \(a-b=2\). 3. The digits that satisfy both conditions are \(a=5\) and \(b=3\).

Answer

\(a=5\), \(b=3\)
5408024
A marker begins at \(\frac{2}{10}\) meter on a path. It moves \(\frac{38}{100}\) meter forward and then \(\frac{1}{10}\) meter backward. a) Show the net movement using hundredths. b) Where does the marker end?

Hints

- Combine the forward and backward movements first. - Express both movements in hundredths before finding the net change. - Convert the starting position to hundredths before adding the net movement.

Solution

1. The net movement is \(\frac{38}{100}-\frac{10}{100}=\frac{28}{100}\) meter forward. 2. The starting position is \(\frac{2}{10}=\frac{20}{100}\) meter. 3. The final position is \(\frac{20}{100}+\frac{28}{100}=\frac{48}{100}=0.48\) meter.

Answer

a) \(\frac{28}{100}\,\text{m}\) forward b) \(\frac{48}{100}\,\text{m}=0.48\,\text{m}\)
5408034
The \(10\times10\) grid represents one whole and has \(74\) shaded squares. Ava and Ben write two decompositions of the shaded amount: Ava: \(\frac{74}{100}=\frac{7}{10}+\frac{4}{100}\) Ben: \(\frac{74}{100}=\frac{6}{10}+\frac{14}{100}\) a) Verify both decompositions. b) Explain how both can represent the same shaded amount.
Figure for problem 540803

Hints

- Rename each tenths addend in hundredths before checking the totals. - Compare the number of tenths in the two decompositions. - Identify the equal-value exchange that connects the two expressions.

Solution

1. Ava’s decomposition is \(\frac{7}{10}+\frac{4}{100}=\frac{70}{100}+\frac{4}{100}=\frac{74}{100}\). 2. Ben’s decomposition is \(\frac{6}{10}+\frac{14}{100}=\frac{60}{100}+\frac{14}{100}=\frac{74}{100}\). 3. Ben uses one fewer tenth than Ava but ten more hundredths. Since \(\frac{1}{10}=\frac{10}{100}\), this exchange does not change the total.

Answer

a) Both are correct: \(\frac{70}{100}+\frac{4}{100}=\frac{74}{100}\) and \(\frac{60}{100}+\frac{14}{100}=\frac{74}{100}\). b) Replacing one tenth with ten hundredths preserves the shaded amount.
5408044
A package contains \(\frac{8}{10}\,\text{kg}\) of clay and \(\frac{16}{100}\,\text{kg}\) of tools. Find the combined mass in kilograms, then express the same mass in grams.

Hints

- Combine the masses before changing the unit. - Express the tenths amount in hundredths of a kilogram. - Relate one hundredth of a kilogram to grams.

Solution

1. Rename \(\frac{8}{10}\) as \(\frac{80}{100}\). 2. The combined mass is \(\frac{80}{100}+\frac{16}{100}=\frac{96}{100}=0.96\,\text{kg}\). 3. Since \(1\,\text{kg}=1000\,\text{g}\), \(0.96\,\text{kg}=960\,\text{g}\).

Answer

\(0.96\,\text{kg}=960\,\text{g}\)
5408054
The whole number \(b\) is from \(0\) through \(99\). The sum \(\frac{9}{10}+\frac{b}{100}\) must be at least \(1.05\) and at most \(1.10\). Find the least and greatest possible values of \(b\).

Hints

- Express the fixed addend and both bounds in hundredths. - Use the lower bound to determine the least possible contribution from \(b\). - Use the upper bound to determine the greatest possible contribution from \(b\).

Solution

1. Rename \(\frac{9}{10}\) as \(\frac{90}{100}\). 2. To reach \(1.05=\frac{105}{100}\), the least possible numerator is \(b=105-90=15\). 3. To stay at or below \(1.10=\frac{110}{100}\), the greatest possible numerator is \(b=110-90=20\).

Answer

Least: \(b=15\) Greatest: \(b=20\)
5408064
The same whole-number numerator belongs in both boxes: \(\frac{4}{10}+\frac{\square}{100}+\frac{\square}{100}=\frac{74}{100}\). Find the numerator and verify the total.

Hints

- Find the combined amount contributed by both boxes. - The two missing addends are equal, so split their combined amount equally. - Substitute the result into both positions to check it.

Solution

1. Rename \(\frac{4}{10}\) as \(\frac{40}{100}\). 2. The two equal missing addends together must be \(\frac{34}{100}\). 3. Each missing addend is \(\frac{17}{100}\), and \(\frac{40}{100}+\frac{17}{100}+\frac{17}{100}=\frac{74}{100}\).

Answer

The numerator is \(17\). Verification: \(\frac{40}{100}+\frac{17}{100}+\frac{17}{100}=\frac{74}{100}\).
5408074
A toy robot follows Route A by moving \(\frac{3}{10}\) meter, then \(\frac{27}{100}\) meter, then \(\frac{1}{10}\) meter. On Route B, it moves \(\frac{5}{10}\) meter and then \(\frac{17}{100}\) meter. Does the robot end the same distance from its starting point on both routes? Show your reasoning by regrouping hundredths, not by using decimal addition.

Hints

- Convert each tenths movement into a count of hundredths. - Combine the moves within each route separately. - Compare the total number of equal-sized parts.

Solution

1. Route A totals \(\frac{30}{100}+\frac{27}{100}+\frac{10}{100}=\frac{67}{100}\) meter. 2. Route B totals \(\frac{50}{100}+\frac{17}{100}=\frac{67}{100}\) meter. 3. The robot ends the same distance from its starting point because each route contains \(67\) hundredths of a meter.

Answer

Yes. Route A totals \(\frac{67}{100}\) meter, and Route B also totals \(\frac{67}{100}\) meter.
5408084
To estimate \(\frac{1}{10}+\frac{58}{100}\), replace \(\frac{58}{100}\) with the nearby value \(\frac{60}{100}\). Find the estimate, state whether it is high or low, and correct it to obtain the exact sum.

Hints

- Compare the original hundredths addend with its nearby replacement. - Decide whether the replacement increased or decreased the sum. - Adjust the estimate by exactly that difference.

Solution

1. The estimate is \(\frac{1}{10}+\frac{60}{100}=\frac{70}{100}=0.70\). 2. The substituted addend is \(\frac{2}{100}\) too large, so the estimate is high by \(\frac{2}{100}\). 3. Correcting gives \(\frac{70}{100}-\frac{2}{100}=\frac{68}{100}=0.68\).

Answer

Estimate: \(0.70\), high by \(0.02\); exact sum: \(0.68\).
5408094
In \(\frac{5}{10}+\square=\frac{82}{100}\), Eli subtracts the visible numerators and proposes \(\frac{77}{100}\) because \(82-5=77\). Explain the unit error and find the correct missing addend.

Hints

- Name the unit counted by each numerator before subtracting. - Convert the tenths addend to hundredths. - Check whether the corrected addend rebuilds the target total.

Solution

1. The numerator \(5\) counts tenths, while \(82\) counts hundredths, so they cannot be subtracted as if they name the same-sized parts. 2. Rename \(\frac{5}{10}\) as \(\frac{50}{100}\). 3. The missing addend is \(\frac{82}{100}-\frac{50}{100}=\frac{32}{100}\).

Answer

Eli mixed tenths with hundredths. Since \(\frac{5}{10}=\frac{50}{100}\), the missing addend is \(\frac{32}{100}\).
5408114
In a photo collection, \(\frac{3}{10}\) are landscapes and \(\frac{42}{100}\) are portraits. The groups do not overlap. What fraction of the collection is neither a landscape nor a portrait?

Hints

- First find the fraction in either named group. - Use the fact that the two groups do not share any photos. - Compare the combined fraction with one whole collection.

Solution

1. Rename \(\frac{3}{10}\) as \(\frac{30}{100}\). 2. Landscapes and portraits together make \(\frac{30}{100}+\frac{42}{100}=\frac{72}{100}\). 3. The remaining fraction is \(1-\frac{72}{100}=\frac{28}{100}=0.28\).

Answer

\(\frac{28}{100}=0.28\)
5408134
For a digit \(d\) from \(0\) through \(9\), consider \(\frac{d}{10}+\frac{d}{100}+\frac{d}{100}\). a) List the digits that make the sum less than \(1\). b) List the digits that make the sum greater than \(1\). c) Does any digit make the sum exactly \(1\)?

Hints

- Express all three addends in hundredths using the same digit. - Compare the combined numerator with \(100\). - Check the boundary between the last sum below one and the first sum above one.

Solution

1. The sum is \(\frac{10d+d+d}{100}=\frac{12d}{100}\). 2. For \(d=0\) through \(8\), \(12d<100\), so the sum is less than \(1\). 3. For \(d=9\), the sum is \(\frac{108}{100}>1\). 4. No digit makes \(12d=100\), so no sum is exactly \(1\).

Answer

a) \(d=0,1,2,3,4,5,6,7,8\) b) \(d=9\) c) No digit makes the sum exactly \(1\).
5408144
Two consecutive whole-number numerators belong in the hundredths addends: \(\frac{8}{10}+\frac{x}{100}+\frac{x+1}{100}=1\frac{13}{100}\). Find \(x\) and verify the equation.

Hints

- Remove the known tenths amount from the mixed-number target. - Translate the remainder into a sum of two consecutive numerators. - Check both missing addends in the original order.

Solution

1. Rename \(\frac{8}{10}\) as \(\frac{80}{100}\) and the target as \(\frac{113}{100}\). 2. The two missing addends total \(\frac{33}{100}\), so their numerators are consecutive numbers with sum \(33\). 3. Those numbers are \(16\) and \(17\), so \(x=16\).

Answer

\(x=16\). Verification: \(\frac{80}{100}+\frac{16}{100}+\frac{17}{100}=\frac{113}{100}=1\frac{13}{100}\).
5408154
Malik says \(\frac{10}{10}=10\), so he writes \(\frac{10}{10}+\frac{23}{100}=10.23\). Explain what the numerator \(10\) counts and correct the sum.

Hints

- Interpret the denominator as the size of each part. - Ask how many tenths make one whole. - Convert the whole to hundredths before adding the remaining fraction.

Solution

1. \(\frac{10}{10}\) means ten parts of size one tenth, which make \(1\), not \(10\). 2. Rename the addends as \(\frac{100}{100}+\frac{23}{100}=\frac{123}{100}\). 3. The correct sum is \(1\frac{23}{100}=1.23\).

Answer

The numerator \(10\) counts ten tenths, which make \(1\). The correct sum is \(1.23\).
5408164
A counter starts at \(\frac{88}{100}\) and moves by \(\frac{1}{100}\) each step. a) How many steps does it take to reach the next tenth? b) How many steps does it take to reach the next whole number? c) Explain why the two numbers of steps are different.
Figure for problem 540816

Hints

- Write each destination in hundredths. - Count the hundredths from the starting value to each destination separately. - Compare the two destination values, not just the step counts.

Solution

1. The next tenth is \(\frac{9}{10}=\frac{90}{100}\). The distance from \(\frac{88}{100}\) is \(\frac{2}{100}\), so it takes \(2\) steps. 2. The next whole number is \(1=\frac{100}{100}\). The distance from \(\frac{88}{100}\) is \(\frac{12}{100}\), so it takes \(12\) steps. 3. The next tenth and the next whole are different landmarks. They are \(10\) hundredths apart.

Answer

a) \(2\) steps b) \(12\) steps c) The next tenth is \(\frac{90}{100}\), while the next whole is \(\frac{100}{100}\); those landmarks are \(10\) hundredths apart.
5408174
One ribbon piece is \(\frac{4}{10}\) meter long, and another is \(\frac{39}{100}\) meter long. a) Find their total length. b) Find the total’s distance from \(\frac{3}{4}\) meter and from \(\frac{8}{10}\) meter. c) Which benchmark is the total closer to?
Figure for problem 540817

Hints

- Express the tenths addend and both benchmarks in hundredths. - Find the exact total before calculating either distance. - The closer benchmark has the smaller difference from the total.

Solution

1. The total is \(\frac{40}{100}+\frac{39}{100}=\frac{79}{100}\) meter. 2. The distance from \(\frac{3}{4}=\frac{75}{100}\) is \(\frac{79}{100}-\frac{75}{100}=\frac{4}{100}\) meter. 3. The distance from \(\frac{8}{10}=\frac{80}{100}\) is \(\frac{80}{100}-\frac{79}{100}=\frac{1}{100}\) meter. 4. Since \(\frac{1}{100}<\frac{4}{100}\), the total is closer to \(\frac{8}{10}\) meter.

Answer

a) \(\frac{79}{100}\,\text{m}\) b) \(\frac{4}{100}\,\text{m}\) from \(\frac{3}{4}\,\text{m}\); \(\frac{1}{100}\,\text{m}\) from \(\frac{8}{10}\,\text{m}\) c) Closer to \(\frac{8}{10}\,\text{m}\)
5408184
Complete the table so every row has a total of \(\frac{73}{100}\). <table><tr><th>Tenths addend</th><th>Hundredths addend</th></tr><tr><td>\(\frac{2}{10}\)</td><td>?</td></tr><tr><td>\(\frac{4}{10}\)</td><td>?</td></tr><tr><td>\(\frac{6}{10}\)</td><td>?</td></tr></table> a) Find the three missing hundredths addends. b) Describe how the hundredths addend changes when the tenths addend increases by \(\frac{2}{10}\).

Hints

- Convert each tenths addend to hundredths. - Subtract each converted addend from the fixed row total. - Compare consecutive rows to identify the compensation pattern.

Solution

1. Rename the tenths addends as \(\frac{20}{100}\), \(\frac{40}{100}\), and \(\frac{60}{100}\). 2. Subtract each from \(\frac{73}{100}\). The missing addends are \(\frac{53}{100}\), \(\frac{33}{100}\), and \(\frac{13}{100}\). 3. Each increase of \(\frac{2}{10}=\frac{20}{100}\) in the first addend requires a decrease of \(\frac{20}{100}\) in the second addend, keeping the total fixed.

Answer

a) \(\frac{53}{100}\), \(\frac{33}{100}\), \(\frac{13}{100}\) b) The hundredths addend decreases by \(\frac{20}{100}\) each row.
5408194
Consider a sum of a tenths fraction and a hundredths fraction. a) Explain why increasing the tenths numerator by \(1\) increases the sum by \(\frac{10}{100}\). b) Give one example of such a sum that is less than \(1\) and one example that is greater than \(1\).

Hints

- Rename one tenth as hundredths before describing the change. - For the first example, choose numerators whose total in hundredths is below \(100\). - For the second example, choose numerators whose total in hundredths is above \(100\).

Solution

1. Increasing the tenths numerator by \(1\) adds one tenth. Since \(\frac{1}{10}=\frac{10}{100}\), the total increases by \(\frac{10}{100}\). 2. For example, \(\frac{2}{10}+\frac{20}{100}=\frac{40}{100}<1\). 3. For example, \(\frac{9}{10}+\frac{20}{100}=\frac{110}{100}>1\).

Answer

a) One additional tenth equals \(\frac{10}{100}\), so the sum increases by \(\frac{10}{100}\). b) Example below \(1\): \(\frac{2}{10}+\frac{20}{100}=\frac{40}{100}\). Example above \(1\): \(\frac{9}{10}+\frac{20}{100}=\frac{110}{100}\).
5408214
Start at \(\frac{43}{100}\). Repeatedly add \(\frac{1}{10}\), then \(\frac{2}{100}\), in that alternating order. a) List the next four values. b) State the total increase after two complete cycles.

Hints

- Convert the tenths step to hundredths before generating the sequence. - Keep the two step sizes in the stated alternating order. - Compare the starting and fourth values to check the total increase.

Solution

1. Rename the first step as \(\frac{1}{10}=\frac{10}{100}\). 2. The next four values are \(\frac{53}{100}\), \(\frac{55}{100}\), \(\frac{65}{100}\), and \(\frac{67}{100}\). 3. One complete cycle increases the value by \(\frac{10}{100}+\frac{2}{100}=\frac{12}{100}\). 4. Two complete cycles increase it by \(2\times\frac{12}{100}=\frac{24}{100}\).

Answer

a) \(\frac{53}{100},\frac{55}{100},\frac{65}{100},\frac{67}{100}\) b) \(\frac{24}{100}\)
5408394
A student finds \(\frac{3}{10}+\frac{46}{100}\) and writes \(0.67\), reversing the digits in the correct hundredths numerator. Explain why the order of the digits matters and give the correct fraction and decimal.

Hints

- Convert the tenths addend before combining numerators. - Keep track of which digit represents tenths and which represents hundredths. - Check the size of the result against the two positive addends.

Solution

1. Rename \(\frac{3}{10}\) as \(\frac{30}{100}\). 2. The sum is \(\frac{30}{100}+\frac{46}{100}=\frac{76}{100}\), not \(\frac{67}{100}\). 3. The digit \(7\) counts tenths and the digit \(6\) counts hundredths, so the correct decimal is \(0.76\).

Answer

\(\frac{76}{100}=0.76\). The digit order matters because \(7\) is in the tenths place and \(6\) is in the hundredths place.
5406604
Use the digits \(2\), \(4\), and \(7\) exactly once in \(\frac{\square}{10}+\frac{\square\square}{100}\). List every arrangement whose sum is less than \(1\), and identify the greatest resulting sum.

Hints

- First determine how many different arrangements are possible. - Group arrangements by the digit in the hundredths place of the two-digit numerator. - Convert the tenths addend to hundredths and evaluate each arrangement. - Check that your list accounts for all six arrangements before choosing the greatest valid sum.

Solution

1. There are \(3\times2=6\) possible arrangements because any of the three digits can be the tenths numerator and the remaining two digits can be ordered in two ways. 2. The arrangements with \(7\) in the hundredths place are \(\frac{2}{10}+\frac{47}{100}=\frac{67}{100}\) and \(\frac{4}{10}+\frac{27}{100}=\frac{67}{100}\). 3. The arrangements with \(4\) in the hundredths place are \(\frac{2}{10}+\frac{74}{100}=\frac{94}{100}\) and \(\frac{7}{10}+\frac{24}{100}=\frac{94}{100}\). 4. The arrangements with \(2\) in the hundredths place are \(\frac{4}{10}+\frac{72}{100}=\frac{112}{100}\) and \(\frac{7}{10}+\frac{42}{100}=\frac{112}{100}\), so they are not less than \(1\). 5. All six arrangements have been checked. The four valid arrangements are listed above, and the greatest resulting sum is \(\frac{94}{100}=0.94\).

Answer

\(\frac{2}{10}+\frac{47}{100}=0.67\) \(\frac{4}{10}+\frac{27}{100}=0.67\) \(\frac{2}{10}+\frac{74}{100}=0.94\) \(\frac{7}{10}+\frac{24}{100}=0.94\) Greatest sum: \(0.94\)
5408204
A craft ribbon has a blue section \(\frac{a}{10}\) yard long and a yellow section \(\frac{b}{100}\) yard long. Together they measure \(\frac{47}{100}\) yard. The value of \(a\) is a digit, and \(b\) is a positive multiple of \(9\). Find \(a\) and \(b\).

Hints

- Express the tenths section in hundredths. - List the possible remainder for the yellow section as the tenths digit changes. - Apply the positive-multiple-of-nine condition, then verify the total.

Solution

1. Express the blue section in hundredths. The numerator equation is \(10a+b=47\). 2. As \(a\) takes the possible values \(0,1,2,3,4\), the possible values of \(b\) are \(47,37,27,17,7\). 3. Only \(27\) is a positive multiple of \(9\), so \(b=27\) and \(a=2\). 4. Check: \(\frac{2}{10}+\frac{27}{100}=\frac{20}{100}+\frac{27}{100}=\frac{47}{100}\).

Answer

\(a=2\), \(b=27\)
5408224
Use the digits \(1\), \(3\), and \(7\) exactly once in \(\frac{\square}{10}+\frac{\square\square}{100}=1.01\). Find every arrangement that makes the equation true.

Hints

- Convert the complete equation to hundredths. - Determine which card must occupy the ones place of the combined numerator. - Test both orders of the remaining digits.

Solution

1. If the tenths digit is \(a\) and the two-digit numerator is \(10b+c\), the total numerator in hundredths is \(10a+10b+c\). 2. The ones digit of \(101\) requires \(c=1\). 3. The remaining digits \(3\) and \(7\) can occupy the two tens positions in either order, giving both valid arrangements.

Answer

\(\frac{3}{10}+\frac{71}{100}=1.01\) and \(\frac{7}{10}+\frac{31}{100}=1.01\)

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