Addition 0-20

Front

0 + 0

Back

0

Front

0 + 1

Back

1

Front

0 + 2

Back

2

Front

0 + 3

Back

3

Front

0 + 4

Back

4

Front

0 + 5

Back

5

Front

0 + 6

Back

6

Front

0 + 7

Back

7

Front

0 + 8

Back

8

Front

0 + 9

Back

9