把千克糖平均分成5份,每份是5千克的.
==12÷ = (小数)
16: == ÷5= %= (填小数)=八折.
甲数比乙数多,甲数与乙数的比是1:4. (判断对错)
=20÷ =0.4=4: = %
= ÷ = (最后结果填小数).