一袋砂糖重500克,2袋砂糖重( )千克.
3:4= :12=12÷ == %
== ÷16= (小数)
5:8= %;0.25的倒数是 .
4÷5==20÷ = (填小数)
=28: =0.8= ÷10= %= .