÷75%= += 0.56÷28=
2.826÷3.14= 0.5×4÷0.5= 0.42=
1.85﹣+= 1÷×= +0.375=
2.4﹣= (+)×2.4= 5÷×5÷=
10×45%= 1.25×8= 40×(1﹣20%)=