Mathletes

simple adding

100

2+5=

7

200

4+8

12

300

5+9

14

400

12+13

25

500

35+46

81

simple subtracting

100

2-2

0

200

5-3

3

300

13-4

9

400

25-12

13

500

52-48

4

harder adding

100

2+3+4

9

200

3+5+7

15

300

5+10+12

27

400

45+12+5

62

500

121+32+15

168

harder subtracting

100

20-4-2

12