①
②
③
④
÷4= ×8= ÷0.4= 1.1×=
÷= ×= 0.52= 478÷83≈
+= 15×8%= 32÷40%= ×
3.14×3= 3.14×5= 3.14×7= 3.14×0.6=
A.1:2:3 B.1:3:5 C.1:1:2 D.2:5:7
①0.83+1.675 ②756+1328 ③+ ④57%+