Explicație pas cu pas:
75 × 6 = (3 × 5 × 5) × 6 = 3 × (5 × 5 × 6) = 3 × (25 × 6) = 3 × 150 = 450
25 × 8 = (5 × 5) × 8 = 5 × (5 × 8) = 5 × 40 = 200
45 × 4 = (3 × 3 × 5) × 4 = 3 × (3 × 5 × 4) = 3 × (15 × 4) = 3 × 60 = 180
36 × 5 = (3 × 2 × 6) × 5 = 3 × (2 × 6 × 5) = 3 × (12 × 5) = 3 × 60 = 180
315 × 8 = (15 × 3 × 7) × 8 = 15 × (3 × 7 × 8) = 15 × (21 × 8) = 15 × 168 = (5 × 3) × 168 = 5 × (3 × 168) = 5 × 504 = 2 520
485 × 4 = (97 × 5) × 4 = 97 × (5 × 4) = 97 × 20 = 1 940
160 × 5 = (80 × 2) × 5 = 80 × (2 × 5) = 80 × 10 = 800