4/5-2/3+1/6 用简便方法计算4/5-2/3+1/6 =4/5-1/2=8/10-5/10=3/10
4/5-2/3+1/6=4/5-1/2=3/10
4/5-2/3+1/6 用简便方法计算 4/5-2/3+1/6 =4/5-1/2 =8/10-5/10 =3/10
