Question

a) Kim rounds the numbers 554 and 16 to the nearest ten. Her estimated difference is 530. Is it Reasonable?____b) Kim uses compatible numbers 555 and 15. Her estimated difference is 540. Is it Reasonable?____

Answer 1

a)

Rounding the numbers 554 and 16 to the nearest ten, we have 550 and 20.

Then, subtracting these numbers, the result is 530.

Therefore the estimated difference is reasonable (YES)

b)

Compatible numbers are numbers easy to perform a mathematical operation.

Kim switched 554 to 555 and 16 to 15, so it's easier to calculate the subtraction.

Subtracting the numbers 555 and 15, the result is 540.

Therefore the estimated difference is reasonable (YES).