Завдання:
Обчисли зручним способом:
1) 25 ⋅ 17 ⋅ 4;
2) 5 ⋅ 137 ⋅ 20;
3) 6 ⋅ 5 ⋅ 39;
4) 500 ⋅ 19 ⋅ 2;
5) 8 ⋅ 685 ⋅ 125;
6) 80 ⋅ 113 ⋅ 5.
Розв'язок:
1) 25 ⋅ 17 ⋅ 4 = 25 ⋅ 4 ⋅ 17 = 100 ⋅ 17 = 1700
2) 5 ⋅ 137 ⋅ 20 = 20 ⋅ 5 ⋅ 137 = 100 ⋅ 137 = 13 700
3) 6 ⋅ 5 ⋅ 39 = 30 ⋅ 39 = 1170
4) 500 ⋅ 19 ⋅ 2 = 500 ⋅ 2 ⋅ 19 = 1000 ⋅ 19 = 19 000
5) 8 ⋅ 685 ⋅ 125 = 8 ⋅ 125 ⋅ 685 = 1000 ⋅ 685 = 685 000
6) 80 ⋅ 113 ⋅ 5 = 80 ⋅ 5 ⋅ 113 = 400 ⋅ 113 = 45 200