用竖式计算.28.7+35.1= 85×34= 52×37=217÷7= 304÷9= 520÷8=
18÷2=÷3=÷4=÷8=
计算:××;×12×;××;××;
××=
计算:××= ××= ×0×= ××=
直接写得数。××=××=××=××4=