Maths Addition

Front 1

1 + 2

Back 1

3

Front 2

2 + 1

Back 2

3

Front 3

1 + 3

Back 3

4

Front 4

3 + 1

Back 4

4

Front 5

1 + 4

Back 5

5

Front 6

4 + 1

Back 6

5

Front 7

1 + 5

Back 7

6

Front 8

5 + 1

Back 8

6

Front 9

1 + 6

Back 9

7

Front 10

6 + 1

Back 10

7

Front 11

1 + 7

Back 11

8

Front 12

7 + 1

Back 12

8

Front 13

1 + 8

Back 13

9

Front 14

8 + 1

Back 14

9

Front 15

1 + 9

Back 15

10