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 :)
I'm not sure if I'd call it the "scientific" one. I'd actually say that the weak juxtaposition is just the simple one schools use because they don't want to confuse everyone. Scientist actually use both and make sure to prevent ambiguity. IMHO the main takeaway is that there is no consensus and one has to be careful to not write ambiguous expressions.
I mean the blog post says
"If you are a student at university, a scientist, engineer, or mathematician you should really try to ask the original author what they meant because strong juxtaposition is pretty common in academic circles, especially if variables are involved like in $a/bc$ instead of numbers."
It doesn't say scientific but...
I’m a scientist and I’ve only ever encountered strong juxtaposition in quick scribbles where everyone knows the equation already. Normally we’re very careful to use fraction notation (or parentheses) when there’s any possibility of ambiguity. I read the equation and was shocked that anyone would get an answer other than 9.
As a Maths teacher, I'm shocked whenever anyone ever gets an answer other than 1. I'm not sure how you came up with 9 when you previously said you've only ever seen strong juxtaposition? You can only get 9 with so-called "weak juxtaposition" (which is wrong).