1 + 7 =
8
15 - 15 =
0
1 + 5 + 4 =
10
10 - 9 =
1
7 + 7 =
14
8 - 3 =
5
3 + 3 =
6
2 + 2 =
4
10 + 1 =
11
9 - 5 - 1 =
3
1 + 1 + 1 + 1 + 1 + 7 =
12
0 + 0 =
0
4 + 4 =
8
6 + 6 =
12
30 - 10 =
20
30 + 0 =
30
