你会计算吗？,56-50=？,56,6,23-3=？,20,我学会啦!,？,20,30,+,=50,70,40,-,=30,40+20=,60-20=,1.,60,40,_+_=_,_+_=_,3.,40,3,43,40,30,70,30+20 40+50 6040,2口算。,3+2 4+5 64,5,9,2,50,90,20,80-50,70+20,20+30,10+80,90-20,30+40,60-40,70-30,60-20
