Question

Isaac drinks 8 glasses of water each day. He says he will drink 2,920 glasses of water in a year that has 365 days. Is the exact answer reasonable? Explain.

Answer 1

Yes because if you check with your math (or a calculator) 365 times 8 is 2,920. Therefore, Isaac's answer is reasonable. Another way you can maybe do it is round 365 days to 370 and 8 to 10 and then multiply. 370 times 10 is 3,700. Since 2,920 is close to 3,700, then the answer is reasonable. 

Hope I helped!!