(-3)÷(-5/3)×(27分之-1)÷9
=-3×3/5×1/27×1/9
=-9/5×1/9×1/27
=-1/5×1/27
=-1/135 （-135分之1）
[-23+(-九分之一)-5/6-(-二十七分之一)]除(-27分之一)
=(-23-1/9-5/6+1/27)×(-27)
=-(-23-1/9-5/6+1/27)×27
=(23+1/9+5/6-1/27)×27
=23×27+1/9×27+5/6×27-1/27×27
=621+3+45/2-1
=621+3-1+22.5
=645.5