× = ÷ = + = 2- =
5.8÷0.1= 20×25%= 15-0.5= 3.82+1.18=
①0.8:2.4=1.5:x
②9:x=1.8:5.6
③4: = :x
④x:10= :
⑤ =
⑥ :25%=x: