3+1= 5+2= 4+3= 1+9= 4+2=
6-3= 9-2= 4-2= 2+8= 9-7=
0+4= 8-8= 0+0= 6-0= 10-8=
10-7= 8-4= 6+3= 4+5= 9-3=