Mental Math
Estimate to 10's
Estimate to 100's
Add 3-digits
Add 4-digits
100

302+56

358

100
478+112

590

100

478+112

600

100

135+152

287

100

2,143+5,199

7, 342

200

463+416

879

200

367+319

690

200

208+164

400

200

372+196

568

200

3,344+1,771

5,115

300

222+725

947

300

737+127

870

300

326+466

800

300

475+264

739

300

3,096 + 2,484

5,580

400

682+115

797

400

519+356

880

400

543+377

900

400

407+436

843

400

 1,908 + 2,563

4,471

500

745+223

968

500

816+145

970

500

498+279

800

500

584+326

910

500

4,146 + 2,351

6,497

M
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