8-1=
10-4=
6+8=
7+7=
7+3=
13-5=
4+5=
13-8=
7+4=
6-2=
15-2=
10-6=
16-8=
9-7=
2+2=
100+100=
3+3=
20-10=
9+9=
7-3=