I wrote a (very long) blog post about those viral math problems and am looking for feedback, especially from people who are not convinced that the problem is ambiguous.
It's about a 30min read so thank you in advance if you really take the time to read it, but I think it's worth it if you joined such discussions in the past, but I'm probably biased because I wrote it :)
This is not a math problem but a calculator engineering problem. Some solve the sub operations from right to left while other do it from left to right.
It's not really a calculator engineering problem. If you don't have time to read the entire blog you should definitely check out the section "But my calculator says...". It's actually about order of operations regarding implicit multiplication.