In math, reasonableness can be defined as checking to verify that the result of the solution or the calculation of the problem is correct or not, be either estimating or by plugging in your result to check it. ... A reasonable estimate does not exceed the original numbers in a problem.

How do you check for reasonableness in math?

Subtract the smaller number from the larger one to check for reasonableness. In this example, you would subtract 600 from 651 to get 51. The numbers are reasonably close, so you can probably accept that 651 is the correct answer.

How do you check for reasonableness in Division?

You can determine if an answer in division is reasonable by learning to estimate the answers. Round the divisor to the nearest 10 or 100, depending on how many digits are in the divisor.