乘法求未知因数练习题
1.1 × ? = 8
2.? × 10 = 50
3.4 × ? = 28
4.? × 8 = 48
5.7 × ? = 28
6.4 × ? = 40
7.? × 4 = 16
8.? × 1 = 8
9.? × 2 = 2
10.9 × ? = 54
11.? × 5 = 15
12.2 × ? = 2
13.? × 7 = 70
14.? × 10 = 40
15.7 × ? = 7
16.? × 1 = 5
17.? × 3 = 24
18.? × 6 = 12
19.? × 10 = 20
20.? × 10 = 30