1) 25 • 17 • 4 = (25 • 4) • 17 = 17 • 100 = 1700;
2) 5 • 137 • 20 = (20 • 5) • 137 = 137 • 100 = 13 700;
3) 6 • 5 • 39 = (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.