Based on this logic raising kids to eat 9/10 of them after roasting them alive would be better than declining to have kids because you disregard the suffering in some sort of interesting moral arithmetic.

The bigger issue is not that nature of the math but the notion that you believe you can subject the matter to it like what is the answer to 42 + banana.

The simpler answer is that we ought to do less immoral things not to find interesting justifications for doing so.