Hello This is question is bugging me for years. Why is division by 0 undefined and not multiplication by 0 undefined? If any number multiplied by 0 is 0 then the logical answer for any number divided by 0 would be ∞ (for me at least). If you "define" N/0=∞ and N*0=undefined then there are no contradictions. Did the mathematicians had to choose between n/0=undefined and n*0=undefined? What about this: n*0=0 0/0=n special rule n/0=∞ ∞*0=n special rule Sorry for my poor english, I am not a native speaker.