①
②
③
④
7.53﹣2.5= 45+215= ×63=
﹣= 24÷= +÷=
0.48÷0.3= 36- = 2.5×40= ×(15+ )=
684+198= 12×1%= × = ×9÷ =
①-÷-
②×+÷8
③(×27-)×
④÷[(+)×]
个
①75.6×27﹣170×7.56