Estimating Sums
Subtraction
Rounding
Estimate Differences
Review
100

144+298

440

100

656-127

529

100

Round to the nearest 10

328

330

100

286-189

100

100

5x4

20

200

271+487

760

200

841-281

560

200

Round to the nearest 10

155

160

200

994-679

310

200

10x10

100

300

225+294

520

300

460-212

248

300

Round to the nearest 100

649

600

300

794-556

250

300

7x6

42

400

365+487

900

400

959-415

544

400

Round to the nearest 100

753

800

400

355-177

175

400

9x8

72

500

291+268

600

500

800-325

475

500

Round to the nearest 10

262



260

500

241-117

120

500

3x5

15

M
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