Addition - subtraction 1-20

6
2
3
9
7
4
10
8
5
14
15
13

6
2
3
9
7
4
10
8
5
15
14
13

16
2
3
9
17
4
14
8
5
8
7
9

16
12
3
9
17
4
14
8
5
7
9
6

16
12
3
9
17
4
14
8
5
5
7
6