46 + 3
46 − 3
28 + 30
73 + 20
96 − 40
87 − 20
8 + 4 − 7
9 + 6 − 8
46 + 3 = 40 + 6 + 3 = 40 + 9 = 49
46 − 3 = 40 + 6 − 3 = 40 + (6 − 3) = 40 + 3 = 43
28 + 30 = 8 + 20 + 30 = 8 + 50 = 58
73 + 20 = 3 + 70 + 20 = 3 + 90 = 93
96 − 40 = 6 + 90 − 40 = 6 + (90 − 40) = 6 + 50 = 56
87 − 20 = 7 + 80 − 20 = 7 + (80 − 20) = 7 + 60 = 67
8 + 4 − 7 = 12 − 7 = 12 − 2 − 5 = 10 − 5 = 5
9 + 6 − 8 = 15 − 8 = 15 − 5 − 3 = 10 − 3 = 7