a) Which number is greater: seven hundred thousand seven or seven hundred seven thousand? Explain your reasoning.
b) Write the number that has \(5\) hundred-thousands, \(2\) ten-thousands, \(8\) hundreds, and \(1\) one.
c) Martina says that nine hundred thousand ninety is written as \(900{,}009\). Explain the error and write the number correctly.
Hints
- Use place-value positions to interpret each number name.
- In part b), account for every place from hundred-thousands through ones, including places with no stated amount.
- For part c), compare the place occupied by the final nonzero digit with the word “ninety.”
Solution
1. Seven hundred thousand seven is \(700{,}007\). Seven hundred seven thousand is \(707{,}000\). Since \(707{,}000 > 700{,}007\), seven hundred seven thousand is greater.
2. For b), the specified place values are \(500{,}000 + 20{,}000 + 800 + 1\). The thousands and tens places contain zeros, so the number is \(520{,}801\).
3. In \(900{,}009\), the final \(9\) is in the ones place, so the number is nine hundred thousand nine. In nine hundred thousand ninety, the \(9\) must be in the tens place. The correct numeral is \(900{,}090\).
Answer
a) Seven hundred seven thousand, or \(707{,}000\), is greater because \(707{,}000 > 700{,}007\).
b) \(520{,}801\)
c) The \(9\) was placed in the ones place instead of the tens place. The correct number is \(900{,}090\).