Multiples of 10
Rounding to Estimate
Multiply by Multiples of 10
Standard Algorithm
100

What is 10 x 10

What is 100

100

What is the estimate of 21 x 14?

What is 200

100

What is the answer to 28 x 10?

What is 2,800

100

Use the standard algorithm to solve 23 x 19?

What is 437

200

What is 20 x 30

What is 600

200

What is the estimate of 43 x 39?

What is 1,600

200

What is the answer to 23 x 30?

What is 690

200

Use the standard algorithm to solve 39 x 33?

What is 1,287

300

What is 40 x 70

What is 2,800

300

What is the estimate of 67 x 53?

What is 3,500

300

What is the answer to 73 x 40?

What is 2,920

300

Use the standard algorithm to solve 62 x 49?

What is 3,038

400

What is 70 x 60?

What is 4,200

400

What is the estimate of 83 x 79?

What is 6,400

400

What is the answer to 64 x 70?

What is 4,480

400

Use the standard algorithm to solve 78 x 73?

What is 5,694

500

What is 90 x 80?

What is 7,200

500

What is the estimate of 93 x 29?

What is 2,700

500

What is the answer to 98 x 80?

What is 7,840

500

Use the standard algorithm to solve 85 x 40?

What is 3,400