把的分子增加12,要使分数值等于,分母应增加 .
=l8: = :20== ÷40= (填小数)
3:8=18÷ ═ %= .小数.
÷8===15÷ = ÷32= (填小数)
0.3==12÷ = :30= %
÷40=20: =0.8= : .