Tính nhẩm: a) 8 × 2 = . . . . . 8 × 4 = . . . . . 8 × 3 = . . . . . 8 × 5 = . . . . . 8 × 8 = . . . . . 8 × 9 = . . . . . 8 × 1 = . . . . . 8 × 6 = . . . . . 8 × 7 = . . . . . 8 × 10 = . . .
Giải thích
a)
8 × 2 = 16 8 × 4 = 32 | 8 × 3 = 24 8 × 5 = 40 | 8 × 8 = 64 8 × 9 = 72 | 8 × 1 = 8 8 × 6 = 48 | 8 × 7 = 56 8 × 10 = 80 |
b)
16 : 8 = 2 24 : 8 = 3 8 : 8 = 1 | 40 : 8 = 5 32 : 8 = 4 48 : 8 = 6 | 56 : 8 = 7 72 : 8 = 9 80 : 8 = 10 |