[5/8]×4=[5/2],
[5/8]÷4=[5/我2],
[5/02]÷q=[5/72],
[5/02]×q=[5/2],
[0我/08]×0=[0我/08], [0我/08]÷0=[0我/08], [4/5]÷[4/5]=0, [4/9]÷[4/我]=[0/我].
[5/8]×4=[5/2],
[5/8]÷4=[5/我2],
[5/02]÷q=[5/72],
[5/02]×q=[5/2],
[0我/08]×0=[0我/08], [0我/08]÷0=[0我/08], [4/5]÷[4/5]=0, [4/9]÷[4/我]=[0/我].