用竖式计算,打★的要验算.627÷33= ;★224÷28= .
5+2= 7-5= 7-2=
4+1= 5-1= 5-4=
2+6= 8-6= 3+3= 6-3=
1+5= 6-1= 10-5= 5+5=
9+0= 9-0= 7+1= 8-1=