六年二班今天出席47人,有3人因病请假,六年二班今天的缺席率是 .
0.625== = ÷40=.
3:4= :12=12÷ == %
== ÷16= (小数)
5:8= %;0.25的倒数是 .
4÷5==20÷ = (填小数)