🦘 Math Kangaroo Grade All Felix 1-2 Ecolier 3-4 Benjamin 5-6 Kadett 7-8 Junior 9-10 Student 11-12 ⇄ switch contest
2016 Math Kangaroo

Problem 2

Problem 2 · 2016 Math Kangaroo Medium
Arithmetic & Operations estimate-and-pick

Which of the following numbers is closest to the number 17×0.3×20.16999?

Show answer
Answer: B — 0.1
Show hints
Hint 1 of 2
You only need a rough size, not the exact value.
Still stuck? Show hint 2 →
Hint 2 of 2
Round each factor and the denominator to easy numbers.
Show solution
Approach: estimation
  1. The top is about 17×0.3×20 ≈ 102.
  2. Dividing by about 1000 gives roughly 0.1.
  3. So the closest listed value is 0.1.
Mark: · log in to save