Multiplication by 1's
1 x 4
4
2 x 3
6
5 x 2
10
10 x 2
20
3 / 1
3
1 x 12
12
2 x 9
18
5 x 5
25
10 x 5
50
10 / 2
5
1 x 27
27
2 x 15
30
5 x 12
60
10 x 10
100
25 / 5
5
1 x 654
654
2 x 50
100
5 x 21
105
10 x 12
120
100 / 10
10
1 x 3,864
3,864
2 x 130
260
5 x 50
250
10 x 20
200
500 / 20
25