6. В каждом столбике найди способ вычислить значение второго выражения. 1) 9 · 7 = 63 9 · 8 2) 12 · 4 = 48 12 · 5 7 · 10 = 70 7 · 9 14 · 5 = 70 14 · 4 15 · 4 = 60 15 · 5 18 · 4 = 72 18 · 3

Ответ: смотри решение

1. 9 ⋅ 7 = 63

   9 ⋅ 8 = 9 ⋅ (7 + 1) = 9 ⋅ 7 + 9 = 63 + 9 = 72

2. 12 ⋅ 4 = 48

   12 ⋅ 5 = 12 ⋅ (4 + 1) = 12 ⋅ 4 + 12 = 48 + 12 = 60

3. 7 ⋅ 10 = 70

   7 ⋅ 9 = 7 ⋅ (10 – 1) = 7 ⋅ 10 – 7 = 70 – 7 = 63

4. 14 ⋅ 5 = 70

   14 ⋅ 4 = 14 ⋅ (5 – 1) = 14 ⋅ 5 – 14 = 70 – 14 = 56

5. 15 ⋅ 4 = 60

   15 ⋅ 5 = 15 ⋅ (4 + 1) = 15 ⋅ 4 + 15 = 60 + 15 = 75

6. 18 ⋅ 4 = 72

   18 ⋅ 3 = 18 ⋅ (4 – 1) = 18 ⋅ 4 – 18 = 72 – 18 = 54

Ответ: смотри решение