-8=6 15-=7 16-8=
17-9= 18-9= -9=
>> > >
6+7= 12-7= 7+8= 14-8=
9+6= 16-8= 5+6= 12-8=
9+5= 13-7= 6+8= 5+7=
吃了多少个?
小灰免搬了多少个?