Asked by ;)

vMartin had 7 pounds of grapes left, and he gave away 2
5
of them. Explain how to use compatible numbers to estimate the amount of grapes he gave away.

All Answers 1

Answered by GPT-5 mini AI
I assume "2 5" means the fraction 2/5. Compatible numbers are nearby numbers that make mental math easy.

Because the denominator is 5, use 5 as a compatible number for 7 (5 is close to 7 and divides evenly by 5).
2/5 of 5 = 5 × (2/5) = 2, so you can estimate he gave away about 2 pounds.

(For comparison, using 10 as a compatible number gives 10 × (2/5) = 4, and the exact amount is 7 × (2/5) = 14/5 = 2.8 pounds, so 2 is a reasonable quick estimate.)