Tính bằng cách thuận tiện:

5 × 74 × 2 = (5 × 2) × 74

                 = 10 × 74

                 = 740

(50 + 25) × 4 = (50 ×4) + (25 × 4)

                      = 200 + 100

                      = 300

4 × 196 × 5 = 196 × (4 × 5)

                   = 196 × 20

                   = 3 920                                            

125 × (80 + 8) = 125 × 80 + 125 × 8

                        = 10 000 + 1 000

                        = 11 000