一个数由3个10,3个0.1,5个0.01组成,这个数是 ,精确到个位是 .
15:90= %==6÷ = :12.
=:0.5= ÷ .
:8===9÷ =27: .
=== ÷5=.
0.4==8÷( )=( )÷5.