4.2÷0.7÷6=6÷6=16.28÷1.25÷8=6.28÷(1.25x8)=6.28÷10=0.628
4.2÷6÷0.7=0.7÷0.7=16.25÷(1.25×8)=6.25÷10=0.625
如图