Topic 8 Review

What is the sum of 243, 132, and 157?

• 523

• 532

• 543

• 542

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

Find a reasonable estimate for the difference of 765 and 333. Select all that apply:

• 770 - 330 = 440

• 600 - 350 = 350

• 800 - 300 = 500

• 700 - 400 = 300

Use mental math to add 332 and 154. Which of these shows how to break apart the numbers into hundreds, tens, and ones?

• Break 332 into 320 + 12. Break 154 into 125 + 29.

• Break 332 into 100 + 230 + 2. Break 154 into 100 + 52 + 2.

• Break 332 into 300 + 16 + 16. Break 154 into 100 + 27 + 27.

• Break 332 into 300 + 30 + 2. Break 154 into 100 + 50 + 4.

How can you check the answer for 693 - 231 = 462?

• Subtract 639 - 300 = 339.

• Subtract 462 - 231 = 231.

• Add 693 + 231 = 924.

• Add 462 + 231 = 693.

Estimate the sum of 123, 201, and 387 by rounding to nearest ten.

• 100 + 200 + 400 = 700

• 120 + 200 + 390 = 710

• 150 + 200 + 350 = 700

• 130 + 210 + 380 = 720

Look at the shaded cells in the addition table above. Which pattern and property of operations are shown in the shaded cells?

• Each orange sum is equal to zero plus the other addend; the Identity Property of Addition

• Each green sum is ten greater than one of its addends; the Identity Property of Addition

• Each green sum is ten greater than the sum before; the Associative Property of Addition

• There are no patterns.

Round each addend to the nearest hundred. Estimate

478 + 112.

• 400 + 100 = 500

• 500 + 100 = 600

• 400 + 200 = 600

• 480 + 110 = 590

Estimate 167 + 27. Use compatible numbers to solve. Select all that apply. * Hint-compatible numbers are close to the numbers and are easy to add mentally. Select all that apply.

• 170 + 30 = 200

• 175 +25 = 200

• 165 + 30 = 195

• 164 + 28 = 192

Round each number to the nearest ten. Estimate 486 - 177.

• 480 - 170 = 310

• 490 - 180 = 310

• 400 - 100 = 300

• 450 - 150 = 300