11+6= 9-8= 15+4= 18-8=
4+6= 16-4 = 7+8= 13-2=
8+3= 19-19 = 20-10 = 4-0=
9+1= 0+3= 12 +4= 6+8=
18-3-4= 15-5+7= 5+5+8= 10-8+9=