Topic 8 Review for Test

What is the sum of 243, 132 and 157?

Find a reasonable estimate for the sum of 171 and 69. Select all that apply.

• 175 + 70 = 245

• 100 + 60 = 160

• 170 + 70 = 240

• 175 + 75 = 250

• 130 + 70 = 200

Which of these shows how to break apart the number 154 into hundreds, tens and ones?

• Break 154 into

  125 + 29

• Break 154 into

  100 + 52 + 2

• Break 154 into

  100 + 27 +27

• Break 154 into

  100 + 50 + 4

Use mental math to find 634 - 528

Select all the equations that are true.

• 32 + 56 + 10 =

  10 + 56 + 32

• (49 +28) + 5 =

  49 + (28 + 5)

• 56 + 890 = 890 + 56

• 82 + 0 = 82

• 45 + 27 = 27 + 35

Look at the table. Which shows the correct way to round to the nearest ten?

• A. 170

  B. 150

  C. 170

  D. 190

• A. 170

  B. 150

  C. 160

  D. 180

• A. 160

  B. 150

  C. 160

  D. 170

Use the inverse operation to check 169 - 57 = 112. Which equation can be used?

• 169 - 57

• 57 + 112

• 112 + 169

• 169 + 57

Subtract 341 - 97 mentally. First add 3 to 97 to get 100. What should the next step be? What is the difference?

• Add 6 to 341. The difference is 247.

• Add 200 to 100. The difference is 100.

• Subtract 3 from 341. The difference is 238.

• Add 3 to 341. The difference is 244.

Estimate the sum of 405 and 385 by rounding to the nearest 100. Type your answer in the blank.

Find the difference.

620 - 278