47.6/0.25/4=47.6/(1/4)/4=47.6*4/4=47.6
47.6/0.25/4=47.6/(0.25/4)=47.6/1=47.6
47.6/(0.25*4)=47.6就OK啦~
47.6*0.25/4=11.9*0.25=2.975