Mental Math Estimate Sums and Differences

Which number is the difference?

• 7

• 4

• 3

The two numbers that we add together are called __________.

• subtraction

• sum

• difference

• addends

Estimate the sum by rounding to the nearest hundred.

382 + 409

Estimate the sum by rounding to the nearest hundred.

297 + 315.

Estimate the sum by rounding to the nearest ten.

629 + 822.

Estimate the difference by rounding to the nearest hundred.

839 - 576

Estimate the difference by rounding to the nearest ten.

737 - 412.

Estimate the difference by rounding to the nearest ten.

944 - 418

Mrs. Green's class collected 414 cans of food during the first week. During the second week, they collected 243 cans. To the nearest ten, about how many more cans did they collect the first week than the the second week?

Estimate the difference by rounding to the nearest hundred.

671 - 357