Most languages throw an error instead, but there are tradeoffs there too. If you've decided not to throw an error you should at least return a usable number and zero makes more sense than -1 or 7 or a billion or whatever.
You could also build the number stack from the ground up to accommodate this edge case, and make it so all arithmetic functions can handle infinities, infinitesimals and limits. I've come across a racket sublang like that but it's nearly unusable for the normal common things you want to do with numbers in code.