SmartmanApps

Ok, then explain prefix and postfix, where these conventions don’t apply

The conventions don't apply, the rules still apply. Maths notation and the rules of Maths aren't the same thing.

How can these be rules of math when they didn’t universally apply?

The rules do universally apply 🙄

The order of operations tells us how to interpret an equation without rearranging it

Yep, and you showed you don't know the rules 🙄

When you pick a different convention, you need to rearrange it to get the same answer

Not necessarily, though it makes it easier (but also leads a lot of people to make mistakes with signs, as you found out 😂 )

What you did was rearrange the equation

To show you how to correctly do "Multiplication first". 🙄

which you can only do if you are already following a specific convention

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.

because the conventions are not laws of mathematics, they are conventions

And putting the Multiplication inside Brackets isn't a convention anywhere 🙄

They obey the laws of math. Conventions aren’t laws of math, they’re conventions

Yep, and you ignored both, hence your wrong answer 🙄

And a quick Google search will tell you that not everyone puts juxtaposition at a higher precedent than multiplication

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 🙄

it’s a convention

No it isn't. It's against the rules. 🙄 Again, you won't find this alleged "convention" in any Maths textbook

As long as people are using the same convention, they’ll agree on an answer and that answer is correct

Unless they disobeyed the rules, in which case they are all wrong 🙄

You can be mean all you like, that doesn’t change the nature of conventions

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 🙄

My doctorate is irrelevant to the truth

It sure is. I've seen a PhD who didn't read the only textbook he had referenced in his thesis, which proved his idea that teachers were doing it wrong and he wasn't, was wrong. 😂 Should've listened to the people who teach it (or actually read the textbook he referenced 🙄 ).

which makes students of math feel inordinately inferior

They don't. All students get this correct. It's only adults who have forgotten the rules that get it wrong.

these gotcha-style math memes IMO deepen students’ belief that they’re just bad at math

Nope. Students never get these wrong.

proofs mean something very specific to me and I can’t yet imagine what that looks like WRT order of operations

All you have to do is see which way gives wrong answers for 2+3x4 and you've proven which ways don't work 😂

note that conventions aren’t necessarily “optional”

Yes they are.

when being understood is essential

You don't understand how to do 2+3x4-5 without knowing which conventions people use for the order of the plus and minus?

Here I am only concerned about the next generation of maths student and how viral content like this can discourage them unnecessarily

It doesn't. None of them get it wrong. 🙄

“No one” in this context meant “no one who actually does maths professionally.”

No it doesn't. Everyone who does Maths professionally does it the same way as in Maths textbooks 🙄

When I see 1+½ i can instantly say “one and a half”

And that would be wrong. It's 1 plus one half. 1½ is one and a half.

when I see 1 + 1 ÷ 2 i actually have to pause for a moment to think about order of operations

You don't know to Divide before Adding??

one I recognize the structure of the problem immediately, and one feels foreign.

Says person with "decades of maths experience outside of textbooks" 🙄

The point is that people who do maths for a living

That would be me

are probably above average in maths, tend to write things differently than people who are stopped their maths education in high school (or lower)

Nope. We all write it the same way as we were taught, even those who have done Maths at University (also me).

these types of memes are designed around making people who know high school maths feel smart

No, they're designed around getting those who have forgotten the rules to argue about it. i.e. engagement bait

and another which says “first multiply two by three, then add it to two”

No we don't. We have another notation which says to do paired operations (equivalent to being in brackets) first.

why on earth do the “rules” have anything further to say about order of operations?

Because if you don't obey them you get wrong answers 🙄

How are you gonna write 2 + 2 ÷ 2 with repeated addition?

You don't, because the second 2 is associated with a Division that has to be done before the addition. Maybe go back to school and learn how to do Maths 🙄

That doesn’t mean it has to be expanded first.

Yes it does. Everything has to be expanded before you do the addition and subtraction, or you get wrong answers 🙄

2+3x4=2+3+3+3+3=2+12=14 correct

2+3x4=5x4=5+5+5+5=20 wrong

You could expand 2 + 2 × 3 as (2+2)+(2+2)+(2+2)

Says someone who can't tell the difference between (2+2)x3=12 and 2+2x3=8 🙄

you are unable to tell me what mathematical law prohibits it

The order of operations rules 😂

reverse polish notation wouldn’t work as it does

It works because it treats every operation as bracketed without writing the brackets. Also that's only a Maths notation, not the Maths itself.

In RPL, 2 2 + 3 × is 12

Because the way it calculates that is (2+2)x3, not complicated. Same order of operations rules as other Maths notations - just a different way of writing the same thing

If you had to expand multiplication first, how would it work?

It works because Brackets - 2 2 + = (2+2) - are before Multiplication

The same can be done with prefix notation

Another Maths notation, same rules of Maths

Different programming languages have different orders of operations

Maths doesn't

those languages work just fine

They don't actually. Welcome to most e-calcs give wrong answers because the programmers failed to deal with it correctly.

Your argument amounts to saying that it makes the most sense to do multiplication before addition

No, my argument is it's a universal rule of Maths, as found in Maths textbooks 🙄

that only gives you a convention, not a rule

Left to right is a convention (as is not writing the brackets in RPN). Brackets before Multiplication before Addition are rules.

knowledge on this subject without qualification

I'm a Maths teacher with a Masters - thanks for asking - how about you?

while ignoring my larger point

You mean your invalid point, that I debunked?

what are conventions if not agreed upon rules?

Conventions are optional, rules aren't.

here is a history of how we actually came to agree upon the aforementioned rules which you may find interesting

He's well-known to be wrong about his "history", and if you read through the comments you'll find plenty of people telling him that, including references. Cajori wrote the definitive books about the history of Maths (notation). They're available for free on the Internet Archive - no need to believe some random crank and his blog.

The rules are about how you interpret the notation

No, the notation definitions are about how to interpret the notation. The rules are about how to do the Maths.

That’s not true

Yes it is

PEDMAS: 8÷2x4 = 4x4 = 16

Yep.

PEMDAS: 8÷2x4 = 8÷8 = 1

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

PE M|D A|S: 8÷2x4 = 4x4 = 16

Yep, same answer regardless of the order 🙄

And thats not even getting into juxtaposition operations,

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.

where fields like physics use conventions that differ from most other field

Nope! The obey all the rules of Maths. They would get wrong answers if they didn't

you’re missing the point

No, you are...

It could be SAMDEP and math would still work

No it can't because no it wouldn't 😂

you’d just rearrange the equation.

Says someone who didn't rearrange "PEMDAS: 8÷2x4 = 8÷8 = 1" and got the wrong answer 😂

The rules don’t change

Hence why "PEMDAS: 8÷2x4 = 8÷8 = 1" was wrong. You violated the rule of Left Associativity

All I can assume from you is that you never did multiple choice questions in University

That would be a wrong assumption.

There’s a reason essay questions are considered easier.

They're not! 😂

Ok than I guess according to you PEMDSA doesn’t work

Oh course it does, and I have no idea why you think I would think otherwise! 😂

Or what about PEDMAS or PEDMSA maybe?

Yep, they all work

Oh wait we made up that order cuz it’s easier to say?

No, you made it up because your country has a chip on it's shoulder about doing it the same way as the rest of the world. 🙄

no one would ever write a problem like this

And yet Maths textbooks do! 😂

when was the last time I saw an X to mean multiplication

In a Maths textbook

1+1÷2 doesn’t even register in my brain properly

You don't know that the obelus means divide??

having an agreed-upon convention absolutely matters for arriving at expected computational outcomes,

Proven rules actually

we call it a convention

No we don't - the order of operations rules

it’s not a “correct” vs “incorrect” principle of mathematics

The rules most definitely are

It’s just a rule we agreed upon to allow consistent results

proven rules which are true whether you agree to it or not! 😂

any good math educator will be clear on this

Yep

If you know the PEMDAS convention already, that’s good, since it’s by far the most common today

No it isn't.

But if you don’t yet, don’t worry

As long as you know the rules then that's all that matters