Within 20
Within 100
without decomposing
composing
Decomposing
100

10+10

20

100

92+7

99

100

51-20

31

100

27+45

72

100

27-9=

18

200

13+8

21

200

47+22

69

200

47-22

25

200

41+29

70

200

53-35

18

300

17+13

30

300

75-23

52

300

97-84

13

300

216+107

323

300

83-28

55

400

19+17=

36

400

67+32

99

400

68-46

22

400

232+177

409

400

196-89

107

500

18+19-

37

500

78-34

44

500

79-58

21

500

662+348

1,010

500

292-164

128

M
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