18 - 1=
4 + 5 =
9 - 7 =
6 + 7=
5 + 9 =
7 + 8 =
9 + 1=
12 + 5=
8 + 4=
3 +12 =
14 - 2=
13
14
17
15
12
10
19 - 8 =
11
