base 10
rounding
estimating
how many 10 in a number
breaking HTO
100

57 + 83

140

100

249 rounded to the nearest 100

200

100

100 + 62

162

100

200

20

100

163 + 247

410

200

526 + 298

824


200

358 rounded to the nearest 10

360

200

1004 + 66

1070

200

500

50

200

636 + 573

1109

300

274 + 956

1220

300

589 rounded to the nearest 25

575

300

2000 + 1693

3693

300

610

70

300

1536 + 738

2274

400

672 + 281

953

400

1567 rounded to the nearest 50

1550

400

1063 + 2047

1100

400

880

88

400

3435 + 653

4088

500

7089 + 2356

9445


500

1789 rounded to the nearest 50

1800


500

2093 + 3869

5962

500

1634

163

500

250 + 586 + 698

1534