1. Вычисли: 307 × 165; 178 × 276; 129 × 634.

307 × 165 = 307 × (100 + 60 + 5) = 30 700 + 18 420 + 1 535 = 50 655.

178 × 276 = 178 × (200 + 70 + 6) = 35 600 + 12 460 + 1 068 = 49 128.

129 × 634 = 129 × (600 + 30 + 4) = 77 400 + 3 870 + 516 = 81 786.