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Algebra Difficulty 1.1 Junior Find the answer Canada

Which of the following is equal to a whole number?

Pick one

Solution

Since 99 is close to 100 and 9 is close to 10, the value of $99\times9$ is approximately equal to $100\times10=1000$ .

Of the given answers, this means that the integer that is closest to $99\times9$ is most likely 1000.

Multiplying, we get that the value of $99\times9$ is 891.
Of the given answers, $99\times9$ is indeed closest to 1000.

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.