(480×2)÷(80×2)= (480×3)÷80=
(480÷5)÷(80÷5)= 480÷(80×2)=
①(227+49)÷12 ②864÷[(32-28)×12]
③88×125 ④24×97+24×3
1.5×1= 910÷70= 2.2﹣1.9= 6÷7= 435+199=
+= -= ÷= 20×= ×=