Сторінки 21 – 25

Завдання 2

3 + 7 + 5 = 10 + 5 = 15           10 – 3 – 5 = 7 – 5 = 2

14 + 5 + 1 = 19 + 1 = 20         100 – 30 – 50 = 70 – 50 = 20

34 + 1 + 5 = 35 + 5 = 40         100 – 50 – 30 = 50 – 30 = 20

3 + 7 – 8 = 10 – 8 = 2              17 – 7 + 4 = 10 + 4 = 14

30 + 70 – 80 = 100 – 80 = 20    34 – 0 + 34 = 34 + 34 = 68

100 + 0 – 0 = 100                     37 – 0 + 0 = 37