I just came across the "Divide 50 by half..." riddle-meme today.
Please don't fall for these. Please don't participate in them. Please just let them die in peace.

- It's a language riddle, not an arithmetic one.
- Specifically, it's a language riddle that tests one of the most difficult, annoying, and subtle parts of most languages: how to use prepositions correctly.
- It's designed to make some people feel smart and others feel stupid, even though intelligence has nothing at all to do with it.

It's a vocabulary test where passing gets you nothing more than failing does. You're no genius for knowing it and no idiot for not knowing it. You either know it or you don't and it almost never matters. It's nice to know, but that's about as far as it goes.

It has perhaps one redeeming quality: it reminds us that languages evolve and that we need to struggle to make ourselves understood and therefore ought to have more compassion for those moments where they fail to understand what we intend to convey.

And that prepositions are arbitrary and confusing.

We're all in this together, folks. Don't volunteer to be pitted against one another like this.

Be excellent to each other.

PS: The wording "divide 50 by half" is clearly and deliberately ambiguous. If we truly mean "divide 50 by 0.5", then we typically say "divide... by *one* half" and if we truly mean "divide 50 by 2", then we typically use another verb, such as "_reduce_... by half". That's it.

PPS: In case English is not your native language, "divide X in half" = "divide by 2", while "divide X by half" = "divide by 1/2" and this is the same as multiplying by 2. That's the entire riddle.

/fin

@jbrains There are regional differences, and a few states in which telling the teacher, "no, you said 'by half'," will get you in trouble for being a smart ass.
@dws Indeed. Very compatible with my point. I wasn't aware of the regional difference, but I was very aware of getting in trouble for being a smartass.
@jbrains Yes, please, so we can stay focused on PEDMAS/BODMAS memes!
@jbrains "
let me guess it has something to do with the difference between "by half" an "in half" ?