一袋大米有20千克,吃了一些后,还剩9千克.吃掉的质量和剩下的质量比是 .
8÷______==2:______=0.4=______%=______成.
5:4=______÷20=______%=
9÷______=75%=______:8==______(填小数)
=______÷______=60%=______:______=______小数.
2.5:______==1.25=25÷______=______%.