this post was submitted on 18 Dec 2025
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If you look at the arguments on math forums, you'll see that there isn't just one rule.
It is a convention, and different places teach different conventions.
Namely, some places say that
PEDMASis a very strict order. Other places say that it isPE D|M A|S, where D and M are the same level and order is left-to-right, and same with addition vs subtraction.And others, even in this post, say it's
PEMDAS, which I have heard before."Correct" and "incorrect" don't apply to conventions, it's simply a matter of if the people talking agree on the convention to use. And there are clearly at least three that highly educated people use and can't agree on.
But they all teach the same rules
Which is totally fine and works
Which is also totally fine and works
Also totally fine and works
No-one has to agree on any convention - they can use whatever they want and as long as they obey the rules it will work
Educated people agree that which convention you use doesn't matter.
That's not true Here is an example:
8÷2x4
PEMDAS: 8÷2x4 = 8÷8 = 1
PEDMAS: 8÷2x4 = 4x4 = 16
PE M|D A|S: 8÷2x4 = 4x4 = 16
And thats not even getting into juxtaposition operations, where fields like physics use conventions that differ from most other field.
but you're missing the point. It could be SAMDEP and math would still work, you'd just rearrange the equation. Just like with prefix or postfix notation. The rules don't change, just the notation conventions change. But you need to agree on the notation conventions to reach the same answer.
Yes it is
Yep.
Nope. PEMDAS: 8x4÷2 = 32÷2 = 16. What you actually did is 8÷(2x4), in which you changed the sign in front of the 4 - 8÷(2x4)= 8÷2÷4 - hence your wrong answer
Yep, same answer regardless of the order 🙄
Which I have no doubt you don't understand how to do those either, given you don't know how to even do Multiplication first in this example.
Nope! The obey all the rules of Maths. They would get wrong answers if they didn't
No, you are...
No it can't because no it wouldn't 😂
Says someone who didn't rearrange "PEMDAS: 8÷2x4 = 8÷8 = 1" and got the wrong answer 😂
Hence why "PEMDAS: 8÷2x4 = 8÷8 = 1" was wrong. You violated the rule of Left Associativity
Ok, then explain prefix and postfix, where these conventions don't apply. How can these be rules of math when they didn't universally apply?
The order of operations tells us how to interpret an equation without rearranging it. When you pick a different convention, you need to rearrange it to get the same answer. What you did was rearrange the equation, which you can only do if you are already following a specific convention.
All conventions can produce the correct answer, when appropriately arranged for that convention, because the conventions are not laws of mathematics, they are conventions.
They obey the laws of math. Conventions aren't laws of math, they're conventions. And a quick Google search will tell you that not everyone puts juxtaposition at a higher precedent than multiplication; it's a convention. As long as people are using the same convention, they'll agree on an answer and that answer is correct.
You can be mean all you like, that doesn't change the nature of conventions
The conventions don't apply, the rules still apply. Maths notation and the rules of Maths aren't the same thing.
The rules do universally apply 🙄
Yep, and you showed you don't know the rules 🙄
Not necessarily, though it makes it easier (but also leads a lot of people to make mistakes with signs, as you found out 😂 )
To show you how to correctly do "Multiplication first". 🙄
Which you didn't, hence why you ended up with a wrong answer. 🙄 There is no textbook which says put the multiplication in Brackets if doing "Multiplication first", none.
And putting the Multiplication inside Brackets isn't a convention anywhere 🙄
Yep, and you ignored both, hence your wrong answer 🙄
And a quick look in the Google support forum will show you many people telling them that is wrong, and Google just closes the incident 🙄
No it isn't. It's against the rules. 🙄 Again, you won't find this alleged "convention" in any Maths textbook
Unless they disobeyed the rules, in which case they are all wrong 🙄
And you can be as ignorant of the rules and conventions of Maths as much as you want, and it's not going to change that your answer is wrong 🙄
Yeah, you clearly don't even know what a convention is, and what are math conventions and math "rules" as you put it.
You're wrong, and even a 2 minute Google search would show you that and explain why. I'm done being Google for you when you're not willing to Google it yourself.
Says person who actually doesn't know the difference, as per Maths textbooks
oh no! you better start contacting all the textbook publishers and tell them that all Maths textbooks are wrong 😂
Even a 2 minute Google search will bring up Maths textbooks which prove that Google is wrong 🙄
Maths teachers don't use Google - that's what Maths textbooks are for
says person who was unwilling to use Google to find Maths textbooks 🙄
Wikipedia
What's that? You don't trust Wikipedia?
Ok, you've yet to explain why notations like prefix and postfix dont need these "rules".
If they were rules of mathematics **itself** how could they only apply to certain notations?
isn't a Maths textbook 🙄 far out, did you learn English from Wikipedia too? You sure seem to have trouble understanding the words Maths textbook
The site that you just quoted which is proven wrong by Maths textbooks, THAT Wikipedia?? 🤣🤣🤣
Umm, they do need the rules! 😂
They don't, they apply to all notations 🙄
I love how confident you are about something you clearly have no knowledge of.
Adorable.
Well, you made a good effort. At least if we're judging by word count.
says person confidently proving they have no knowledge of it to a Maths teacher 🤣
from Maths textbooks, which for you still stands at 0
To a "maths teacher"
Yeah sure
A "teacher" who doesn't know that all lessons are simplifications that get corrected at a higher level, and confidentiality refers to children's textbook as an infallible source of college level information.
A "teacher" incapable of differentiating between rules of a convention and the laws of mathematics.
A "teacher" incapable of looking up information on notations of their own specialization, and synthesizing it into coherent response.
Uh huh, sounds totally legit
Don't bother mate. Even if you corner them on something, they absolutely will not budge.
I like many others brought up calculators and how common basic calculators only evaluate from left to right. They contend that this is not true and that calculators have always been able to obey order of operations. I even linked the manuals of two different calculators which both had this operation.
He asserted (without evidence) that the first does not operate in this way (even though the manual says that you must re-order some expressions so that bracketed sub-expressions come first). He then characterised the second as a "chain calculator" for "niche purposes". So he admits it works left-to-right, but still will not admit that he was wrong about his claim.
This calculator thing is not central to the discussion on order of operations, but it goes to show: you will not convince him of anything no matter what the evidence is.
By the way, after reading a few of his comments, I believe I can summarise his whackadoodle understanding if you want to continue tilting at windmills: he fundamentally cannot separate mathematics from the notation. Thus he distinguishes many things which are the same but which are written differently.
As opposed to a Maths teacher who knows there are no corrections made at a higher level. Go ahead and look for a Maths textbook which includes one of these mysterious "corrections" that you refer to - I'll wait 😂
A high school Maths textbook most certainly is an infallible source of "college level" information, given it contains the exact same rules 😂
Well, that's you! 😂 The one who quoted Wikipedia and not a Maths textbook 😂
You again 😂 Wikipedia isn't a Maths textbook
Man, this whole post has been embarrassing for you. Oof.
I can't help but notice youve once again failed to address prefix and postfix notations.
And that you've not actually made any argument other than "nuh uh"
Not to mention the other threads you've been in. Yikes.
We can all tell you're not a maths teacher.
Nope. I'm the only one who has backed up what they've said with Maths textbooks 🙄
What is it that you want addressed?
Backed up by Maths textbooks 🙄
Says person who actually isn't a Maths teacher, hence no textbooks 😂
Your argument you haven't made is backed up by math textbooks you haven't provided written for children.
How can that specific order of operations be a law of mathematics if it only applies to infix notation, and not prefix or postfix notations? Laws of mathematics are universal across notations.
Show me a textbook that discusses other notations and also says that order of operations is a law of mathematics.
You don't have it, and you also aren't a maths teacher, or a teacher at all. Just because you say it a lot doesn't make it true.