Question

Explain how you could estimate 22% of 78 to check if your answer is reasonable.

Answer 1

22 percent = about 1/5
78 is close to 80

so divide 80 by 5 to give a good estimate

Answer 2

Well, 22% is roughly (just over double) 10%. 10% of 78 is 7.8. So if you double that, you get 15.6. So 15.6 (or round up to 16) is ROUGHLY 22% of 78. To check that take 0.22 and multiply times 78. That is 17.16. This number is not to far off from 16...so you would be right to say 16 is ROUGHLY 22% of 78.