Dude's phone gave correct answer. 5/0 = ∞ What you really can't do (with numbers) - is divide zero by zero. Also you cant multiply infinity by zero. And subtract infinity from infinity. And divide infinity by infinity. And so on. But! Despite that you can't do it with numbers, you can with limits-of-sequences. By the way, before learning calculus you need to learn how to deal with limits. http://en.wikipedia.org/wiki/Limit_of_a_function http://en.wikipedia.org/wiki/Limit_of_a_sequence

I suppose you could define division by zero to give some value, and have basically the same result, but it would not be the inverse of multiplication in that particular instance. define newdiv(a,b){ if (b==0){ return somespecialsymbol; }elseif(b isa complexNumber){ return olddiv(a,b); }else{ throw outOfDomainError; } } yeah. don't know why I just typed that out. this apparently doesn't allow for spaces for indentation... yep.