Joseph has 16 pretzels for snack. He gives some of them to isabella. Now he has 9 left. How many pretzels did he give to isabella?

Question

Estimate! Is the estimate reasonable Does it make sense

Answer 1

If an estimate is required, 9 is approximately 10, so if we remove the tens digit we get 6 as the number left.

But since 9 is one less than 10 he will have one more than 6 left, which is 7.