32 − 7
43 − 9
56 − 8
83 − 6
28 + 8
57 + 7
100 − 2
100 − 6
32 − 7 = (30 + 2) − 7 = 2 + (30 − 7) = 2 + 23 = 25
43 − 9 = (40 + 3) − 9 = 3 + (40 − 9) = 3 + 31 = 34
56 − 8 = (50 + 6) − 8 = 6 + (50 − 8) = 6 + 42 = 48
83 − 6 = (80 + 3) − 6 = 3 + (80 − 6) = 3 + 74 = 77
28 + 8 = 28 + 2 + 6 = 30 + 6 = 36
57 + 7 = 57 + 3 + 4 = 60 + 4 = 64
100 − 2 = (90 + 10) − 2 = 90 + (10 − 2) = 90 + 8 = 98
100 − 6 = (90 + 10) − 6 = 90 + (10 − 6) = 90 + 4 = 94