400÷80= 7.7+2.3= 4.2÷0.6= 1﹣0.91=
0.04×1000= 10÷1.25×9= 24×0.25= 23﹣1=
+= ×20=
①
②
③1.25×88+12.5×1.2
④
+= ×= -= ÷=
0.18×= 4.7+0.38= 3.2÷0.1= (10﹣)×0=