0.8%×17×125%=(8/1000)×17×(125/100)=(17×8×125)/(1000×100)=(17×1000)/(1000×100)=0.1718÷0.25=18÷1/4=18×4=7260×(5/12-1/5)=60×5/12-60×1/5=25-12=13（80-9.8）×0.6-2.12=70.2×0.6-2.12=70×0.6+...