When I multiply, I take it in chunks.
Put the LLM into a loop, instruct it to keep track of where it is and have it solve a digit at a time.
I bet it does just fine. See my other comment as to why I think that is.
If we were to take the stance of "ok, that happened so it must be the case" we wouldn't be better off in many cases, we would still be accusing people of being witches most likely.
Science is about coming up with a theory and trying to poke holes into it until you can't and in which case, after careful peer-review to ensure you're not just tricking yourself into seeing something which isn't there a consensus is approached in which we can continue to build more truth and knowledge.
(I’m specifically talking about commercial hosted ones that have the capability i describe - obviously your run of the mill one downloaded off of the internet cannot do this).