In Japan, the order of multiplication is discussed online.

How much does it cost to buy five apples for 50 yen each?

At school, 50x5 = 250 is correct, and writing 5x50 = 250 is incorrect.

Many mathematicians say that the order of multiplication is meaningless, but some school teachers do not change their mindset. :0point:

@mayuutann This is a horrible thing to do. Japan just lost generations worth of mathematicans with this because there are actually a bunch of kids good in math what make leisure from experimenting with their knowledge making ways to themselves to build new approaches.

This is such a wasted potential :blobcatoh:

Albert Einstein was actually a kid like this as I learned from his biography. He started playing and then mastering math and wondering about the world's rules in a young age and actually getting terrible qualities in a punishing school system.

@RealPurrplenekoboi >Japan just lost generations worth of mathematicans

Yeah, I think so, too. :ohdear:
Yeah, I respect Einstein too. :blobderpy:

@mayuutann Wow. That's a great way to stopping the kids from thinking logically and understanding what multiplication really is, on a fundamental level.

@snowyfox maybe no. At least I've never heard that. maybe some teachers mind only order of multiplication. 🤔

@mayuutann that's super silly, I hope they only do that on lower grades or something
@shpuld @mayuutann butyou: "why did you write the multiplication the wrong way? please redo the report"

@shpuld They only do that on primary school. But people worry about that children will hate math. Because it ’s not wrong, but it ’s wrong. :ohdear:

@mayuutann it's wrong to teach that the order matters

@angristan @mayuutann i'll be writing 5x50 = 250 on anything I publish from here on out, just to rock the boat.

@resist1984 @angristan hahaha, but it seems that the order of teaching is different depending on the country. So that maybe be correct. 😅

@mayuutann Synonyms or near-synonyms, were the only reason I didn't get max scores on my English vocabulary tests here. Because our teach absolutely refused to accept the answer if we didn't memorize the exact translation in the book.

For example if I translated a word into "waste" or "garbage", instead of "trash", which was written in the book, I'd lose that point.

Some teachers are just really fucking strict about the most pointless things and it sucks.

We had one teacher who kept nagging about the order of multiplication too, but at least he didn't subtract actual points for it. He'd usually write an annoying comment next to the answer every time we "messed" up the multiplication order though.
@mayuutann Knowing Japan, I guess your teacher are pretty strict in general?

@quad Ahh, he isn't my teacher. This is a discussion that is currently a hot topic in Japan. 😅

@mayuutann Ah okay, I'm glad I never had a teacher who actually subtracted points for something like that in maths. I did in English though.
@mayuutann That sounds like enforcing a style guide. I could see it making it faster to grade tests if all the answers will look more uniform.

@brad yes. Perhaps the teachers who care about the order is to let them do what they taught. :blobmelt:

@mayuutann IIRC in Japan you're not allowed to prove your superior wrong, so I'm not surprised.

I mean both have good reasons.
One the one hand: Multiplication within the complex numbers is commutative and therefore the result doesn't change. So the order doesn't matter.
On the other hand: There are many other operators and structures on which multiplication is not commutative (e.g. matrix-matrix multiplication).

Of course for just multiplying with "normal" numbers it's fine to ignore order but in a strict technical sense it doesn't, it just doesn't change the result.

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