Bài Làm:
1.
a) 4 x 6 = 6 x 4 207 x 7 = 7 x 207 |
b) 3 x 5 = 5 x 3 2138 x 9 = 9 x 2138 |
2.
a) 1357 x 5 = 6785 |
7 x 853 = 5971 |
b) 40263 x 7 = 281 841 | 5 x 1326 = 6630 |
3.
4 x 2145 | (2100 + 45) x 4 |
3964 x 6 | (4 + 2) x (3000 x 964) |
10287 x 5 | (3 + 2) x 10287 |
4.
a) a x 1 = 1 x a = a
b) a x 0 = 0 x a = 0