的分子扩大4倍,要使分数的大小不变,分母应扩大 倍.如果分子加上4,要使分数大小不变,分母应扩大 倍.
3÷ == :12=七成五= %
=0.75=15÷ .
9: == ÷32== :56.
:16==0.125= %
=0.75= : .