Multiplying by 4

Front

4 x 3

Back

12

Front

5 x 4

Back

20

Front

6 x 4

Back

24

Front

4 x 4

Back

16

Front

4 x 0

Back

0

Front

8 x 4

Back

32

Front

4 x 7

Back

28

Front

4 x 8

Back

32

Front

9 x 4

Back

36

Front

4 x 8

Back

32