Show:
addition to 20
subtraction to 20
addition to 100
subtraction to 100
addition w/ RG
100

8+7=

15

100

20-20=

0

100

60+30=

90

100

90-60=

30

100
47+23=

70

200

9+5=

14

200

18-9=

9

200

55+30=

85

200

98-43=

55

200

65+76

141

300

10+9-

19

300

15-12=

3

300

67+21=

88

300

83-11

72

300

39+41

80

400

7+5=

12

400

19-7=

12

400

43+31=

74

400

67-52=

15

400

34+59

93

500
8+9=

17

500

20-19

1

500

74+15=

89

500

100-99

1

500

45+89=

134