Номер 328
Обчисліть зручним способом:
1) 12 • 25 = 12 • (5 • 5) = (12 • 5) • 5 = 60 • 5 = 300;
2) 42 • 50 = 42 • (5 • 10) = (42 • 5) • 10 = 210 • 10 = 2100;
3) 125 • 24 = 125 • (8 • 3) = (125 • 8) • 3 = 1000 • 3 = 3000;
4) 48 • 500 = 48 • (5 • 100) = (48 • 5) • 100 = 240 • 100 = 24000;
5) 7 • 28 • 250 = 7 • 28 • (25 • 10) = (7 • 25) • (28 • 10) = 175 • 280 = 49000;
6) 25 • 9 • 5 • 16 = (25 • 9) • (5 • 16) = 225 • 80 = 18000.