ADD.

    1 + 3 =

ADD.

    2 + 3 =

ADD.

    3 + 1 =

ADD.

    1 + 1 =

Subtract:

4 - 3 =

Subtract:

5 - 2 =

ADD.

    1 + 2 =

ADD.

    2 + 3 =

Subtract:

3 - 2 =

Subtract:

2 - 1 =

ADD.

    2 + 1 =

Subtract:

3 - 1 =

Subtract:

2 - 2 =

ADD.

    3 + 1 =

Subtract:

5 - 3 =