19-8=
16-7=
12-4=
15-9=
17-6=
20-8=
15-7=
12-9=
18-7=
16-8=
14-9=
20-6
13-9=
17-4=
14-8=
15-9=
12-6=
14-7=
12-5=
14-5=
16-7=
15-8=
14-6=
13-8=
11-6=
12-7=
12-3=
13-4=
20-9=
18-9=
20-7=
12-4=
19-6=
12-8=
20-4=
20-3=
8+9=
7+6=
4+7=
9+3=
5+6=
6+7=
7+8=
4+9=
8+8=
9+9=
7+7=
6+6=
5+5=
4+4=
4+9=
5+8=
7+9=
8+6=
8+9=
7+8=