①x:3=:
②=
③:=:x
④:x=3:12
⑤:x=5%:0.6
⑥=
9×3.14= +÷= 36×= 728﹣299=
72÷0.4= 75×10%= 1÷×= 12.56÷6.28=
①273﹣73﹣27
②1.25×9.78×80
③()×24
④[1﹣()]÷