56 9-17+3 6-5+32-1
109 2+610-5 9-5-13+0
A.3 B.10 C.4
3+7= 16-2= 16-5= 10-3+8= 9+0+4=
10-2= 8+8= 7+5= 12+7-10= 16-4-2=
3+10= 7+7= 4+9= 2+4+7= 13+5-8=
8+3= 7+4= 6+11= 9+3+1= 15+3-5=
(个)