（0.375×一又五分之四÷6.3×5.4）÷（2.7÷2.1×八分之一×3.6） =（3/8*9/5/6.3*5.4)/(2.7/2.1*3.6/8) =3*9*5.4/(8*6.3*5)/(9/7*0.45) =27*6/(280)*700/(9*45) =27*60*70/(280*9*45) =3*4/(4*3) =1
