脱式计算过程方法如下解:76.97-18.75-1.25=76.97-(18.75+1.25)=76.97-20=56.97
76.97-18.75-1.25=76.97-(18.75+1.25)=76.97-20=56.97
原式=76.97-(18.75+1.25)=76.97-20=56.97