Show:
Doubles
Counting On
10 more
10 less
Subtracting
100

5 + 5 =

10

100

18 + 3 =

21

100

10 + 10 =

20

100

20 - 10 =

10

100

10 - 6 =

4

200

6 + 6 =

12

200

29 + 2 =

31

200

40 + 10 =

50

200

40 - 10 =

30

200

20 - 2 =

18

300

8 + 8 =

16

300

90 + 4 =

94

300

75 + 10 =

85

300

65 - 10 =

55

300

37 - 3 =

34

400

9 + 9 =

18

400

87 + 4 =

91

400

88 + 10 =

98

400

77 - 10 =

67

400

50 - 20 = 

30

500

40+40 =

80

500

99 + 3 =

102

500

93 + 10 =

103

500

106 - 10 =

96

500

99 - 98 =

1