Problem 4 · 2025 Math Kangaroo
Easy
Arithmetic & Operations
estimate-and-pick
Which interval contains the value of the product \(77 \times 777\)?
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Answer: D — between 7 777 and 77 777
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Hint 1 of 2
Round each factor to a nearby round number to bound the product.
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Hint 2 of 2
77 is near 80 and 777 near 800, so the product is roughly 60 000.
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Approach: size estimation by bounding
- 77 × 777 ≈ 80 × 800 = 64 000.
- The exact value 59 829 sits between 7 777 and 77 777.
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