Show:
Mental Math
Estimate Sums
Estimate Differences
Add Whole Numbers
Add Larger Numbers
100

60 seconds

14 + 36

50

100

12 + 76

90

100

76 - 12

70

100

12 + 24

36

100

320 +180

500

200

50 seconds

31 + 40

71

200

24 + 59

80

200

49 - 21

30

200

51 + 23

74

200

437 + 320

757

300

40 seconds

23 + 150

173

300

113 + 29

130

300

105 - 23

80

300

145 + 21

166

300

650 + 150

800

400

30 seconds

205 + 110

315

400

139 + 287

400

400

373 - 121

300

400

135 + 216

351

400

442 + 401

843

500

20 seconds

140 + 430

570

500

432 + 399

800

500

729 - 268

400

500

253 + 160

413

500

1,001 + 230

1,231