180+20×4 75×3+207 (410-385) ×9
1.5×1= 910÷70= 2.2﹣1.9= 6÷7= 435+199=
+= -= ÷= 20×= ×=
① []
②4.6+7.68﹣1+2.32
③1.25×2.5×0.4×8
④9.5×20%+