this post was submitted on 18 Dec 2025
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[โ€“] SmartmanApps@programming.dev 1 points 3 days ago (1 children)

snipping replies into tiny segments and replying shortly to each makes the discussion much harder to follow

Says person who did it in a random order, and included stuff that wasn't even in this thread to begin with, thus making it impossible to follow ๐Ÿ™„

this is the most interesting thing youโ€™ve said

You on the other hand haven't said anything interesting, so do us all a favour and give it a rest

you can write your 14 litres of milk as 2 + 3 x 4

You "can" write it the way it's always been written, yes ๐Ÿ˜‚

But if you had right-to-left order of operations

Which we don't ๐Ÿ™„

you could not write this as 2 + 2 x 3 = 8 litres

Right, you would write 3x2+3x2 ๐Ÿ˜‚

youโ€™d have to insert brackets: (2 + 2) x 3 = 12 litres

Or you just write it correctly to begin with, then Factorise

But with left-to-right order you could write this as 2 + 2 x 3 = 12

No you can't. As you already pointed out 2+2x3=8. ๐Ÿ˜‚ Have you forgotten that we already do evaluate left to right??

where one translates readily to BODMAS order without brackets

Dating back many centuries before we even started using brackets in Maths ๐Ÿ˜‚

the other translates readily to L2R order without brackets

Umm, it's the same one ๐Ÿ˜‚

interpreted correctly

Welcome to the order of operations rules - so glad you could finally join us

Yes, if you incorrectly translate my scenario as 2 + 2 x 3 with BODMAS order, you get the wrong answer

What you mean is you get the wrong answer, having written it out wrongly to begin with ๐Ÿ™„

the problem into mathematical notation using L2R order, then evaluated the expression using BODMAS order

They're the same order ๐Ÿ˜‚

the problem with one convention then evaluating that with another is wrong!

No it isn't! ๐Ÿ˜‚ All conventions give the same answer. Disobeying the rules on the other hand...

axiomatisation and write the proof

Umm, there's no axioms involved, and I already showed you the proof ๐Ÿ™„

order of operations is about notation

Nope. It's about rules. That's why everyone the world over gets the same answers regardless of the notation they use in the different countries

constitutes a proof. It does not

says someone revealing they only know about the two types of proof, not all the others ones as well ๐Ÿ™„

Here is the mathematical definition of a proof in a first order theory

Which is one type of proof ๐Ÿ™„

no room for milk and bottles in a proof

There's room for Cuisenaire rods though. Welcome to even a 3rd grader can prove it ๐Ÿ˜‚

trying to establish that itโ€™s wrong

I already proved it's wrong ๐Ÿ™„

itโ€™s adding nothing beyond restating what youโ€™re already saying

And yet, you keep ignoring that it's been proven correct Mr. Ostrich, hence I need to keep repeating it ๐Ÿ™„

imaginary third-grader

I can assure you that they aren't imaginary! ๐Ÿ˜‚

writing down 2 + 2 x 3 = 12

Ah, nope! They would write 3x2+3x2

if you taught him or her the right-to-left convention

We taught them first how to use Cuisenaire rods, then the order of operations rules, which follows on logically from there ๐Ÿ™„

all confidently incorrect.

says person about to prove that they are the one who is confidently incorrect... ๐Ÿ˜‚

Note especially the phrase: โ€œMany simple calculators without a stackโ€

Note the lack of a reference ๐Ÿ™„

chain calculation mode) is commonly employed on most general-purpose calculators

No it isn't. It's only employed by calculators designed to use chain calculations, which is another specialist, niche market, like RPN calculators. Note again the lack of a reference

an example of a calculator manual from the 70s showing (in Example 6) that the order of operations is left-to-right

BWAHAHAHAHAHAHA! No it doesn't! ๐Ÿคฃ๐Ÿคฃ๐Ÿคฃ It shows you to press the +/= button after the bracketed part in order to evaluate that first, because, if you don't, it will evaluate the Multiplication first, as per the order of operations rules, which it will use the stack for. ๐Ÿ˜‚ When you press the x button, the parser know you meant the previous button press to be used as an equals and not as addition. You need to work on your reading/comprehension skills dude

the successor

A chain calculator, so this is just you rehashing your RPN argument with a different, niche notation

you have forgotten these old, basic calculators

says person who forgot to check that the manual agrees before posting it, leading to proof that they are the ones who have forgotten how they work! ๐Ÿคฃ๐Ÿคฃ๐Ÿคฃ

now weโ€™ve established that youโ€™re confidently incorrect

No, we've established that you are the one who is confidently incorrect ๐Ÿ˜‚

Windows calculator being โ€œwrongโ€ in its emulation of stackless calculators

We've established that isn't what it's doing, given it's not called Chain mode, it's called Standard mode, which it most definitely isn't! ๐Ÿ˜‚

letโ€™s bring this back to the point

Yep, that point being that simple calculators, like the first one, will say 2+3x4=14. To get 20 you have to do 2+3=x4 ๐Ÿ˜‚

even though their order of operations is left-to-right

only chain calculators do it left to right. You're making a false equivalence argument, just like RPN was a false equivalence argument

I said before: it had a different convention for a sensible reason

Which you just proved the first one doesn't have a "different convention". ๐Ÿ˜‚ The second one does, but again that's a false equivalence argument to all other calculators (same for RPN)

if you expect something different it is you who are using the device wrong

You proved they both do exactly what I expect ๐Ÿ˜‚

How to use the device is written in the manual

Which you didn't read carefully ๐Ÿคฃ๐Ÿคฃ๐Ÿคฃ

so every user of it can use it correctly

As I have been, the whole time

if you want to continue this discussion, please acknowledge that you were wrong about this.

Except you just proved that you were the one who was wrong about this! ๐Ÿคฃ๐Ÿคฃ๐Ÿคฃ I expect you are now going to acknowledge that you were wrong about this, because otherwise you're exposing yourself as a hypocrite

This is a simple, verifiable matter of fact that youโ€™ve been shown to be wrong about

Nope, you were shown to be wrong ๐Ÿคฃ๐Ÿคฃ๐Ÿคฃ

as above, the different calculators have different conventions

As above, only niche calculators like RPN and Chain have different conventions, and it's right there in their manual, that you didn't read carefully

all through this that order of operations is not merely a convention, but a rule. So, itโ€™s not actually about textbooks

Which part didn't you understand about the rules can be found in Maths textbooks?

your spilled milk establishes the opposite of what you want it to

Umm, no it doesn't. It establishes that there is only one correct answer to 2+3x4, that being 14

textbooks are all you have

and calculators, and Cuisenaire rods, and counting up, and proofs ๐Ÿ˜‚

if all the textbooks were edited overnight to teach L2R order of operations

They already do teach left to right! ๐Ÿ˜‚

Children would learn that to add 2 litres of milk to 3 bottles of 4 litres, they ought to write 2 + (3 x 4)

No, they would learn the same thing they learn now 2+3x4. You know they haven't been taught about brackets yet, right? They don't learn about brackets until Year 5

The textbooks are, in fact, how you can see that this is just a convention

No, Cuisenaire rods show that this is a rule. ๐Ÿ™„ That's why kids are shown how to use them before they first learn how to multiply

If the textbooks changed, only what people write would change

Because notations change but the rules don't ๐Ÿ™„

youโ€™ve been linking havenโ€™t been about order of operations

There's dozens here - knock yourself out! ๐Ÿ˜‚

There is no โ€œdefinition of multiplicationโ€ here

In other words, not the right tool for the job. Glad you finally worked that out! ๐Ÿ˜‚

a convention is a social construct

And the rules aren't ๐Ÿ™„

The definition exists

In your mind maybe, not in Maths textbooks, as I would've told you at the time (wherever it was - you're now referring to something that isn't even in this thread originally, so I don't even know what you're talking about anymore)

Saying โ€œwe donโ€™t have itโ€ doesnโ€™t make sense

And I still don't know where you're having trouble in understanding that

Iโ€™ve told it to you

And I told you that we don't have that definition ๐Ÿ™„

so now you have it;

And I told you that you were wrong ๐Ÿ™„

the choice of convention Iโ€™m saying youโ€™re making

I've been talking about rules the whole time Mr. Ostrich

what is it then?

Proof by disproof ๐Ÿ™„

first-order arithmetic, the + symbol is a binary operation

So now you're resorting to the minority of the population that has studied that at University. Way to admit you're wrong in the general case ๐Ÿ˜‚

Weโ€™re not โ€œleaving it outโ€ in front of the 2

High school Maths textbooks, which everyone does, explicitly say it's there

So far you have not even tried to write down what it would mean for the test to be wrong

What part didn't you understand in 20 litres is the wrong answer?

I can lay out my definition of โ€œitโ€™s a matter of conventionโ€ easily

Because you keep ignoring that they are proven rules Mr. Ostrich ๐Ÿ™„

everything could be done another way

Actually it can't. Go ahead and try, and you'll find that out eventually

be consistent with itself and with physical reality

That's the exact thing which prevents it from being done another way ๐Ÿ™„

[โ€“] FishFace@piefed.social 0 points 2 days ago* (last edited 2 days ago) (1 children)

You have declined to admit to a simple error you made (that early calculators lacked a stack, and that basic four function calculators all did and still do)

There's no point having a discussion with someone so stubborn that they can't admit a single mistake. I'm not sure whether you're trying to wind people up or just a bit dim, but while it's fun explaining mathematics - especially parts like this which touch on the formal parts and the distinction between maths itself and mathematical convention - this conversation is like trying to explain something to a particularly stuck-up dog. Except dogs aren't capable of being snarky.

The real tragedy is that you claim to be out there teaching kids this overcomplicated and false drivel.

Anyway, if you want to continue the discussion - maybe with a whiteboard would be best - I'm quite happy to, but only if you show that you're not just a troll. You can do that by admitting that you were wrong to say that all calculators have stacks, which shouldn't be hard if you have a shred of honesty, because I showed you two examples.

Another way you could demonstrate your good faith by admitting a mistake is admitting that when you said, in this post that:

Maths textbooks never use the word โ€œjuxtapositionโ€

you were wrong, and that this screenshot which I believe you first linked demonstrates it. In case that image disappears, it's from Advanced Algebra by J.V. Collins, pg 6.

On page 3, the concept of juxtaposition is introduced.

So that's an extra way you could demonstrate your good faith, by admitting to an error on your part not central to your argument that will show you actually are capable of admitting error.

[โ€“] SmartmanApps@programming.dev 0 points 1 day ago (1 children)

You have declined to admit to a simple error you made

Not me, must be you! ๐Ÿ˜‚

that early calculators lacked a stack,

They didn't ๐Ÿ™„

that basic four function calculators all did and still do

Have a stack, yes. I have one and it quite happily says that 2+3x4=14, something it can't do without putting "2+" on the stack while it does the 3x4 first ๐Ÿ™„

Thereโ€™s no point having a discussion with someone so stubborn that they canโ€™t admit a single mistake.

says someone too stubborn to admit making a mistake ๐Ÿ™„

Iโ€™m not sure whether youโ€™re trying to wind people up or just a bit dim

Neither. I'm the one doing fact-checks with actual, you know, facts, like my simple calculator having a stack and correctly evaluating 2+3x4=14. It's the one I had in Primary school. The one in the first manual works the exact same way

this conversation is like trying to explain something to a particularly stuck-up dog

So maybe start listening to what I've been trying to tell you then. ๐Ÿ™„ It's all there in textbooks, if you just decide to read more than 2 sentences out of them.

The real tragedy is that you claim to be out there teaching kids this overcomplicated and false drivel.

Facts, as per the syllabus and Maths textbooks. Again, you need to read more than 2 sentences to discover that ๐Ÿ™„

only if you show that youโ€™re not just a troll.

says person who has thus far refused to read more than 2 sentences out of the textbook ๐Ÿ™„

You can do that by admitting that you were wrong to say that all calculators have stacks

I wasn't wrong ๐Ÿ™„ The first manual that was linked to proved it. If you don't press the +/= button before the multiply then it will put the first part on the stack and evaluate the multiplication first, something it doesn't do if you press the +/= first to make it evaluate what you have typed in so far. ๐Ÿ™„ Every calculator will evaluate what you have typed in so far if you press the equals button, as pointed out in the first manual

because I showed you two examples

The first of which had a stack ๐Ÿ™„ the second of which was a chain calculator, designed to work that way. You're the one being dishonest

you were wrong

No I wasn't

that this screenshot

Which is a 1912 textbook. It also calls Factorising "Collections", and The Distributive Law "The Law of Distribution", and Products "Multiplication". Guess what? The language has changed a little in the last 110 years ๐Ÿ™„

itโ€™s from Advanced Algebra by J.V. Collins, pg 6

Yep, published in 1912

On page 3, the concept of juxtaposition is introduced

And we now call them Products. ๐Ÿ™„ You can see them being called that in Modern Algebra, which was published in 1965. In fact, in Lennes' infamous 1917 letter, he used the word Product (but didn't understand, as shown by his letter), so the language had already changed then

admitting to an error on your part

There was no error. The language has changed since 1912 ๐Ÿ™„

you actually are capable of admitting error

Of course I am. Doesn't mean I'm going to "admit" to an error when there is none ๐Ÿ™„

[โ€“] FishFace@piefed.social 1 points 1 day ago* (last edited 1 day ago)

You failed to demonstrate any good faith so this is the end of this conversation. Your reply reveals that you even understand that you were wrong ("it's designed that way"; "the language changed") but are so prideful, so averse to ceding ground, that you just.. can't.. say it!

I'm not sure you have enough theory of mind to understand what that's like for a normal interlocutor, unfortunately.

The children you really ought to stop teaching are more mature than this. You're an embarrassment to the profession.