12-1= 7-0= 4-4=
2+8= 8+1= 4+2=
□○□=□(人)
13+4= 18-7= 11+6= 17-4=
14+3= 14-4= 12+7= 20-8=
16+2= 19-3= 14+2= 16-5=
17+2= 15-9= 5+7= 9-1+3=
19-6= 8-2= 8+4= 16-2+4=
16+4= 20-2= 6+7= 4+8-3=
11-4= 12-5= 8+3= 14+2-3=
17-3-7= 13+3-10= 11-4+6= 10-4+11=