This shower thought seems grounded heavily in ignorance of math
and teaching
Hell, most people don’t even learn exactly the same fucking rules.
Yes they do, but sure, go ahead and produce a Maths textbook which teaches different rules to all the others (I've never seen one yet) - I'll wait 😂
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the proper way is to group it as 1+(-2)+3
No it isn't.
you can do it in any order
You can do it in any order anyway
left to right 1-2+3=-1+3=2
addition first 1+3-2=4-2=2
subtraction first -2+1+3=-1+3=2
right to left 3-2+1=1+1=2
What I meant with ““rule”” is the meme questions pray on people not understanding/remembering what the actual rules are
And you showed that you were one of them. Every answer you got other than 4 was wrong, because you didn't understand the rules. spoiler alert: doing it in different orders never means add brackets to it. Addition first for 10-1+1 is 10+1-1, not 10-(1+1). See previous textbook example
why “left to right” conventions exist
They exist because people like you make mistakes when you try to do it in a different order. Either learn how the rules work or stop spreading disinformation. Well, you should stop spreading disinformation regardless.
I fully agree that if it comes down to “left to right”
It never does
But I’ve just shown why that “rule” is a common part
No you didn't. You showed you didn't understand the rules. Doing addition first for 10-1+1 is 10+1-1, not 10-(1+1). It literally means add all positive numbers together first, which are +10 and +1, as per Maths textbooks...
Note in the above simplification of the coefficients we have 6-11+5-7+2=6+5+2-11-7=13-18=-5, and not, as you claim 6-(11+5)-(7+2)=6-16-9=-19
because it is so weird and quite esoteric
It's a convention, not a rule, and as such can be completely ignored by those who understand the rules. See literal textbook example
Maandelykse Mathematische Liefbebbery, Purmerende (1754-69)
You know the Facebook post is in English and from 2025, right? 😂
At least that’s not how I’ve been taught in school
If you had a bad teacher that doesn't mean everyone else had a bad teacher.
You’re not teaching kids how to prove the quadratic formula, do you?
We teach them how to do proofs, including several specific ones.
No, you teach them how to use it instead.
We teach them how to use everything, and how to do proofs as well. Your whole argument is just one big strawman.
Again, with the order of operations
Happens to be the topic of the post.
It’s not a thing
Yes it is! 😂
I’ve given you two examples that don’t follow any
So you could not do the brackets first and still get the right answer? Nope!
2×2×(2-2)/2=0
2×2×2-2/2=7
That’s kinda random, but sure?
Not random at all, given you were talking about students understanding how Maths works.
2+3×4 then it’s not an order of operation that plays the role here
Yes it is! 😂 If I have 1 2-litre bottle of milk, and 4 3-litre bottles of milk, there's only 1 correct answer for how many litres of milk of have, and it ain't 20! 😂 Even elementary school kids know how to work it out just by counting up.
They all derive from each other
No they don't. The proof of order of operations has got nothing to do with any of the properties you mentioned.
For example, commutation is used to prove identity
And neither is used to prove the order of operations.
2 operators, no order followed
Again with a cherry-picked example that only includes operators of the same precedence.
You have no property that would allow for (2+3)×4 to be equal 2+3×4
And yet we have a proof of why 14 is the only correct answer to 2+3x4, why you have to do the multiplication first.
Is that not correct?
Of course it is. So what?
It literally has subtraction and distribution
No it didn't. It had Brackets (with subtraction inside) and Multiplication and Division.
I thought you taught math, no?
Yep, and I just pointed out that what you just said is wrong. 2-2(1+2) has Subtraction and Distribution.
2-2 is 2 being, hear me out, subtracted from 2
Which was done first because you had it inside Brackets, therefore not done in the Subtraction step in order of operations, but the Brackets step.
Also, can you explain how is that cherry-picking?
You already know - you know which operations to pick to make it look like there's no such thing as order of operations. If I tell you to look up at the sky at midnight and say "look - there's no such thing as the sun", that doesn't mean there's no such thing as the sun.
You teach how to solve equations, but not the fundamentals
Nope. We teach the fundamentals. Adults not remembering them doesn't mean they weren't taught. Just pick up a Maths textbook. It's all in there. Always has been.
Fundamentals, most of the time, are taught in universities
No they're not. They only teach order of operations from a remedial point of view. Most of them forget about The Distributive Law. I've seen multiple Professors be told by their students that they were wrong.
it’s not really math in a sense that you don’t understand the underlying principles
The Constructivist learners have no trouble at all understanding it.
Nope.
Yep!
There’s only commutation, association, distribution, and identity.
And many proofs of other rules, which you've decided to omit mentioning.
It doesn’t matter in which order you apply any of those properties, the result will stay correct
But the order you apply the operations does matter, hence the proven rules to be followed.
2×2×(2-2)/2
Notably you picked an example that has no addition, subtraction, or distribution in it. That's called cherry-picking.
Completely different order, yet still correct
Yep, because you cherry-picked a simple example where it doesn't matter. It's never going to matter when you only pick operations which have the same precedence.
My response to the rest goes back to the aforementioned
...cherry-picking.
No, I am saying you are wrong
And textbooks, calculators, accountants, and @sxan@midwest.social, who also explicitly pointed out that what you did was 10-(1+1). I see you didn't read the textbook either then.
No one else
Nope, also all the other parties listed above, who all agree with me
The saddest, and funniest, part is that you are so egotistical that you don’t see why you are wrong
That would be you again, after it has been explained to you many times, by me, other commentators, and Maths textbooks.
Maybe you will get it one day, but I won’t be there for it
Again that applies to you only, the only one here who thinks 10-1+1=8 when doing addition first, even though 11-1=10.
Self reflection is good.
How do you know when you haven't tried it yet? If you had, you would realise you also owe @cabron_offsets@lemmy.world an apology too
I know it is wrong, which is why I am telling you what my mistake was originally
But failing to understand what your actual mistake was, coming up with -1+1=-2, and not -1+1=-0
The fact that you still don’t get it demonstrates your complete lack of understanding
That would be you, the one who thinks order matters, and that -1+1=-2, not -0.
Order does matter
Nope!
+10-1+1=10
+10+1-1=10
-1+10+1=10
+1+10-1=10
+1-1+10=10
-1+1+10=10
Put those all into a calculator, and/or ask an accountant about it.
that order is left to right.
And yet, going RIGHT TO LEFT +1-1+10=0+10=10, same answer... though I have no doubt you think it's +1-1+10=+1-11=-10
The original equation is written correctly
and 10-(1+1) isn't, hence your continued wrong answer
My mistake was doing the addition before the subtraction when the equation reads 10 - 1 + 1
No, your mistake was doing 10-(1+1) where the question reads 10-1+1, and not +10+1-1 <== this is addition first, you add all the positive numbers together first, then do the negative numbers This is literally the textbook way to do it
According to you 6a²b-11a²b+5a²b-7a²b+2a²b=6a²b-16a²b-9a²b=-19a²b, and yet the textbook quite clearly states it's -5a²b, which is because it's 6a²b+5a²b+2a²b-11a²b-7a²b=13a²b-18a²b, and NOT 6a²b-(11a²b+5a²b)-(7a²b+2a²b)
10-(1+1)=10-1-1 which is what you did, which is not 10-1+1. You "added" 1 to -1, and got -2 instead of 0
How are you still not getting this?
It's not me who's not getting it.
No it wasn’t.
Yes it was. Read the textbooks.
The original equation is written correctly but the logic is incorrect
No your logic is incorrect. You're incorrectly adding brackets to it.
in order to make it work the way I declared you have to do the equation x - y + z doing the y + z first
By putting it in brackets which is not how addition is done first. Doing addition first for x - y + z is x + z - y, not x - (y + z)
which was the mistake doing addition then subtraction
No, the mistake was you put the addition in brackets, -(1+1)=-2, not -1+1=+1-1=0. As per the textbook, the sum of any 2 numbers can only have 1 value. That 1 value for -1 and +1 is 0. -1+1=0, +1-1=0, not -1+1=-2
doing addition then subtraction instead of addition and subtraction in order from left to right
The rules are you either do addition then subtraction, OR you do left to right. There is no such thing as addition then subtraction left to right.
Addition then subtraction 10+1-1=11-1=10
Left to right 10-1+1=9+1=10
What you did 10-(1+1)=10-2=8
I see you are still being a bad teacher
says bad student, who didn't try what the teacher said to try
who refuses to listen
that would be you again. You didn't try it on a calculator, you didn't ask an accountant. You didn't even read and understand my examples. Read the textbook - it's not just me telling you this.
I am not continuing with you
Because you're unwilling to admit you're wrong and refuse to try what the teacher and textbook have told you to do, and also refuse to ask an accountant about it
The fact that you still don’t get it demonstrates bad faith
Nope, that's you again. You're even arguing with literal textbook examples.
willful ignorance, and an unwarranted superiority complex
Also you, thinking you're above Maths teachers, calculators, accountants, and Maths textbooks. According to you all of us are wrong, and only you are right. Get a grip
Yes, a video, by Gerald of the MAUI team.
Looks like you're on mobile, so not sure if it works the same, but on PC these are the 2 places you can click and it takes you straight into the video (works for me)
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You seem to be under the mistaken impression that all that is needed to teach something is to know it, thus ignoring what teachers are taught to do when they get their teaching qualifications.
It would need to be a calculator which gives correct answers, which therefore leaves out some Texas Instruments calcs and almost all e-calcs (welcome to what happens when programmers don't check their Maths first when writing a calculator). The Windows calc in Standard mode says 2+3x4=20. Turns out teachers need to know how to do Maths without a calculator.
And learn how to teach, just like Maths teachers also have to do (well, not in the U.S., but that's another story).
No, you have to have a skill level of being able to teach it to all types of students. If you have to teach students that 1+1=2, and you don't know why 1+1=2, and a student asks you why 1+1=2, what are you going to do then? If teaching was nothing more than passing on facts then we could just give every kid books on the subject and do away with school.
You got that the wrong way around. What's taken for granted by advanced Maths classes is what you are taught only in lower Maths classes. Welcome to a whole bunch of Professors don't know the correct answer to order of operations problems because they don't teach it and have forgotten the rules 😂