Сторінки 74 – 75

Завдання 3

8 + 4 = 8 + 2 + 2 = 10 + 2 = 12

28 + 4 = 28 + 2 + 2 = 30 + 2 = 32

38 + 4 = 38 + 2 + 2 = 40 + 2 = 42

78 + 4 = 78 + 2 + 2 = 80 + 2 = 82

9 + 7 = 9 + 1 + 6 = 10 + 6 = 16

39 + 7 = 30 + (9 + 7) = 30 + 16 = 46

69 + 7 = 60 + (9 + 7) = 60 + 16 = 76

89 + 7 = 80 + (9 + 7) = 80 + 16 = 96

5 + 8 = 8 + 5 = 8 + 2 + 3 = 13

25 + 8 = 25 + 5 + 3 = 30 + 3 = 33

55 + 8 = 55 + 5 + 3 = 60 + 3 = 63

75 + 8 = 75 + 5 + 3 = 80 + 3 = 83

7 + 5 = 7 + 3 + 2 = 12

47 + 5 = 40 + (7 + 5) = 40 + 12 = 52

67 + 5 = 60 + (7 + 5) = 60 + 12 = 72

87 + 5 = 80 + (7 + 5) = 80 + 12 = 92