Question

Robert earned $37.38 on Monday, $20.46 on Tuesday, and $49.84 on Wednesday. He calculated that he earned $87.22 for the three days.

Estimate the amount Robert earned. Is his calculation reasonable?

Answer 1

there's a couple of ways you could estimate this. one way could be to round each # to the nearest 10

for example, 37.38. since we're rounding to the nearest ten, we look at the tens digit, which is the very first digit 3. then, moving to the next digit, 7, this is greater than 5 so we round up to 40

repeat this process with the other two numbers, then add the results. compare your result to Robert's estimation and explain why it is or is not reasonable, depending on how close it is