用竖式计算,并验算.48.5+47.25= ;20.8﹣6.48= .
18÷2=÷3=÷4=÷8=
计算:××;×12×;××;××;
××=
计算:××= ××= ×0×= ××=
直接写得数。××=××=××=××4=