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2015 Math Kangaroo

Problem 1

Problem 1 · 2015 Math Kangaroo Easy
Arithmetic & Operations estimate-and-pick

Which of the following numbers is closest to the product of 20.15 × 51.02?

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Answer: B — 1000
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Hint 1 of 2
You don't need the exact product — round each factor to something friendly.
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Hint 2 of 2
Estimate 20.15 × 51.02 as 20 × 51 and compare to the powers of ten offered.
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Approach: estimate the product by rounding
  1. Round 20.15 to 20 and 51.02 to 51.
  2. 20 × 51 = 1020.
  3. Of the listed numbers, 1000 is closest.
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