20个16是 ,180是9的 倍.
=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= : .