This kind of problem falls under “communicating badly and acting smug when misunderstood”. Use parenthesis and the problem goes away.
on that note, can we please have parentheses in language. i keep making ambiguous sentences
This is why grammar is important, and “grammar nazis” are the only good kind of nazis.
We have them in written language, though?
People try and use commas for this sort of clarification and are eviscerate for it.
With these sort of math problems, the rules are taught early and then all subsequent math is written in an unambiguous form.
Language has the oddity of going the other way around where the rules get more complex as a display for advanced skills.
eviscerated
God, can you even spell???
Get your act together./s
My language teachers always told me it was bad form to use too much or even to nest parenthesis…
Then I found lisp…
Lost In Stupid Parenthesis.
Isn’t that basically what commas are for?
Why (I don’t see) not
This kind of problem falls under “communicating badly and acting smug when misunderstood”.
No it doesn’t. It falls under adults forgetting the rules of Maths.
Use parenthesis and the problem goes away
There is no problem, other than adults who have forgotten the rules.
This thread shows that a whole bunch of people need to start taking online education courses. Getting back your algebra skills, some science perhaps, communication, history, etc.
I don’t know where you can get a proper education for that after grade school, but I see Brilliant.org advertised a lot.
question: is there something more than the expression evaluating to 11?
This is the kind of post designed to invoke a reaction. Facebook’s and pretty much every other algorithm driven social media is designed to promote posts that have high interaction. So a post that invokes lots of negative reactions gets lots of promotion. Hence the downfall of modern society.
Ah, yes. It’s only for genius.
What’s the scam?
11
deleted by creator
OK, it’s been a few hours. I’ll do the clumsy thing that everyone else has avoided and point out that it’s deliberately set up so that people who have never heard of operator precedence - those who do things purely left-to-right - don’t get a weird fraction when the division step is done, making them think that the answer they’ve reached must be the right one. You’d still get a handful who’d argue regardless, but that whole number ropes in a whole bunch more.
Couple that with the fact that the value reached this way doesn’t match the value obtained from using operator precedence and you get arguments about what the right answer is. And a comment like the one you’re reading right now that’s too long for the hard-of-thinking to read.
“More engagement, baybee [sunglasses smiley emoji] [cash bag emoji]” etc.
Not strictly a scam, but there’s a little money to be made creating viral content on Facebook. They receive a tiny portion of the ad revenue from Facebook when they generate engagement.
It’s just Facebook sucking really.
Thanks 🙏
Boomers and Xgens need to prove, that they remember basic school math in FB lmao.
Gen xers? Don’t irk them. They’re not noticing you right now.
Very independent, and cranky generation.
Please don’t include X with the boomers. Since we stepped into the real world and realized it functions completely differently than what we were raised to believe, life’s just been a neverending string of “wait, that was wrong too?” We just want to survive another day under the radar.
Sorry fellow X’rs for publicly acknowledging our existence. Hopefully this post doesn’t get any upvotes. *Pulls blanket back over my head.
The average home buyer in the US 17 years ago was born in 1968. Today? 1968. Yeah excuse me but as an elder millennial, Gen X can mostly fuck right off.
You understand that gen x starts around 1965, right? Your stat says they’re mostly getting fucked too.
You understand that gen x starts around 1965, right?
10 years earlier than that actually. Johnny Rotten, Billy Idol, etc. The U.S. came late to the party and started using their own definition.
And you understand that 68 is after 65? They’re not getting. Fucked, they’re the last ones to be able to afford housing ownership. If the average is 68 that means one side of the bell curve extends well into the generation.
As a millennial, I’m starting to relate more and more. The world changes very quickly, and all of the sudden things you knew as fact have different meanings, and there are new words and stuff. It’s not all bad change, but it’s change, and odds are, I’m finding out something changed the hard way.
Seriously, I was raised with so much propaganda.
Up until my late twenties I had believed basically everything I was taught in school. I never had reason to question it, as I was basically living in a bubble. Imagine my surprise when I discovered that when the colonists arrived to this country, it wasn’t just big empty open spaces that the native Americans gladly shared with us. Funny enough, that’s roughly when I gained access to the internet.
The first rule of gen-x is you don’t talk about gen-x!
Who, the people who never had calculators in their pockets growing up? No worries, we can do math better than you.
lmao
Knowing basic arithmetic does not mean you know Math, and the fact you so hung up about this trivial aspect says a lot about you. Additionally, you express yourself like a boomer.
I’m more worried about the gratuitous comma and what it means for the state of education.
What, gratuitous, comma?
The one after the prove.
Nah, people can write things while being a bit drunk, you know. I’m speaking for a friend, not me, ofc.
÷ could be a minus sign, see: https://en.wikipedia.org/wiki/Division_sign?wprov=sfla1
÷ could be a minus sign
No it couldn’t.
Did you check the reference? It says % can be used as a minus sign, not the obelus. Welcome to what happens when you’re next-door neighbour Joe Blow can edit Wikipedia.
Yes I did, on page 243:
It was employed in the Philosophical Transactions by the Dutch astronomer N. Cruquius; ÷ is found in Hübsch and Crusius. It was used very frequently as the symbol for subtraction and ``minus´´ in the Maandelykse Mathematische Liefbebbery, Purmerende (1754-69)
Except that it has English text above it…
So order of operations is hard?
So order of operations is hard?
Not for students it isn’t. Adults who’ve forgotten the rules on the other hand…
The issue normally with these “trick” questions is the ambiguous nature of that division sign (not so much a problem here) or people not knowing to just go left to right when all operators are of the same priority. A common mistake is to think division is prioritised above multiplication, when it actually has the same priority. Someone should have included some parenthesis in PEDMAS aka. PE(DM)(AS) 😄
The issue normally with these “trick” questions
There’s no “trick” - it’s a straight-out test of Maths knowledge.
the ambiguous nature of that division sign
Nothing ambiguous about it. The Term of the left divided by the Term on the right.
A common mistake is to think division is prioritised above multiplication
It’s not a mistake. You can do them in any order you want.
when it actually has the same priority
Which means you can do them in any order
“A common mistake is to think division is prioritised above multiplication”
That is what I said. I said it’s a mistake to think one of them has a precedence over the other. You’re arguing the same point I’m making?
I said it’s a mistake to think one of them has a precedence over the other
And I said it’s not a mistake. You still get the right answer.
You’re arguing the same point I’m making?
No, I’m telling you that prioritising either isn’t a mistake. Mistakes give wrong answers. Prioritising either doesn’t give wrong answers.
The same priority operations can be done in any order without affecting the result, that’s why they can be same priority and don’t need an explicit order.
6 × 4 ÷ 2 × 3 ÷ 9 evaluates the same regardless of order. Can you provide a counter example?
Another person already replied using your equation, but I felt the need to reply with a simpler one as well that shows it:
9-1+3=?
Subtraction first:
8+3=11Addition first:
9-4=5Addition first: 9-4=5
Nope. Addition first is 9+3-1=12-1=11. You did 9-(1+3), incorrectly adding brackets and changing the answer (thus a wrong answer)
So let’s try out some different prioritization systems.
Left to right:
(((6 * 4) / 2) * 3) / 9 ((24 / 2) * 3) / 9 (12 * 3) / 9 36 / 9 = 4Right to left:
6 * (4 / (2 * (3 / 9))) 6 * (4 / (2 * 0.333...)) 6 * (4 / 0.666...) 6 * 6 = 36Multiplication first:
(6 * 4) / (2 * 3) / 9 24 / 6 / 9Here the path divides again, we can do the left division or right division first.
Left first: (24 / 6) / 9 4 / 9 = 0.444... Right side first: 24 / (6 / 9) 24 / 0.666... = 36And finally division first:
6 * (4 / 2) * (3 / 9) 6 * 2 * 0.333... 12 * 0.333.. = 4It’s ambiguous which one of these is correct. Hence the best method we have for “correct” is left to right.
Right to left:
6 * (4 / (2 * (3 / 9)))
Nope! 6 × 4 ÷ 2 × 3 ÷ 9 =4 right to left is 6 ÷ 9 x 3 ÷ 2 × 4 =4. You disobeyed the rule of Left Associativity, and your answer is wrong
Multiplication first: (6 * 4) / (2 * 3) / 9
Also nope. Multiplication first is 6 x 4 x 3 ÷ 2 ÷ 9 =4
Left first: (24 / 6) / 9
Still nope. 6 × 4 x 3 ÷ 2 ÷ 9 =4
Right side first: 24 / (6 / 9)
Still nope. 6 × 4 x 3 ÷ 9 ÷ 2 =4
And finally division first: 6 * (4 / 2) * (3 / 9)
And finally still nope. 6 ÷ 9 ÷ 2 x 4 x 3 =4
Hint: note that I never once added any brackets. You did, hence your multiple wrong answers.
It’s ambiguous which one of these is correct
No it isn’t. Only 4 is correct, as I have just shown repeatedly.
Hence the best method we have for “correct” is left to right
It’s because students don’t make mistakes with signs if you don’t change the order. I just showed you can still get the correct answer with different orders, but you have to make sure you obey Left Associativity at every step.
I stand corrected
I stand corrected
No, you weren’t. Most of their answers were wrong. You were right. See my reply. 4 is the only correct answer, and if you don’t get 4 then you did something wrong, as they did repeatedly (kept adding brackets and thus changing the Associativity).
It’s ambiguous which one of these is correct. Hence the best method we have for “correct” is left to right.
The solution accepted anywhere but in the US school system range from “Bloody use parenthesis, then” over “Why is there more than one division in this formula why didn’t you re-arrange everything to be less confusing” to “50 Hertz, in base units, are 50s-1”.
More practically speaking: Ultimately, you’ll want to do algebra with these things. If you rely on “left to right” type of precedence rules re-arranging formulas becomes way harder because now you have to contend with that kind of implicit constraint. It makes everything harder for no reason whatsoever so no actual mathematician, or other people using maths in earnest, use that kind of notation.
The solution accepted anywhere but in the US school system range from “Bloody use parenthesis, then” over “Why is there more than one division in this formula why didn’t you re-arrange everything to be less confusing” to “50 Hertz, in base units, are 50s-1”.
No, the solution is learn the rules of Maths. You can find them in Maths textbooks, even in U.S. Maths textbooks.
so no actual mathematician, or other people using maths in earnest, use that kind of notation.
Yes we do, and it’s what we teach students to do.
I fully agree that if it comes down to “left to right” the problem really needs to be rewritten to be more clear. But I’ve just shown why that “rule” is a common part of these meme problems because it is so weird and quite esoteric.
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
I know it’s not a rule, hence why I put it in quotation marks. I noted in another comment that, yes, the proper way is to group it as 1+(-2)+3 and you can do it in any order. What I meant with ““rule”” is the meme questions pray on people not understanding/remembering what the actual rules are or why “left to right” conventions exist.
Maybe I’m wrong but the way I explain it is until the ambiguity is removed by adding in extra information to make it more specific then all those answers are correct.
“I saw her duck”
Until the author gives me clarity then that sentence has multiple meanings. With math, it doesn’t click for people that the equation is incomplete. In an English sentence, ambiguity makes more sense and the common sense approach would be to clarify what the meaning is
100% with you. “Left to right” as far as I can tell only exists to make otherwise “unsolvable” problems a kind of official solution. I personally feel like it is a bodge, and I would rather the correct solution for such a problem to be undefined.
It’s so we don’t have to spam brackets everywhere
9+2-1+6-4+7-3+5=
Becomes
((((((9+2)-1)+6)-4)+7)-3)+5=
That’s just clutter for no good reason when we can just say if it doesn’t have parentheses it’s left to right. Having a default evaluation order makes sense and means we only need parentheses when we want to deviate from the norm.
It’s so we don’t have to spam brackets everywhere
No it isn’t. The order of operations rules were around for several centuries before we even started using Brackets in Maths.
((((((9+2)-1)+6)-4)+7)-3)+5
It was literally never written like that
we only need parentheses when we want to deviate from the norm
That has always been the case
100% with you. “Left to right” as far as I can tell only exists to make otherwise “unsolvable” problems a kind of official solution
It’s not a rule, it’s a convention, and it exists so as to avoid making mistakes with signs, mistakes you made in almost every example you gave where you disobeyed left to right.
until the ambiguity is removed
There isn’t any ambiguity.
all those answers are correct
No, only 1 answer is correct, and all the others are wrong.
Until the author gives me clarity then that sentence has multiple meanings. With math
Maths isn’t English and doesn’t have multiple meanings. It has rules. Obey the rules and you always get the right answer.
it doesn’t click for people that the equation is incomplete.
It isn’t incomplete.
Can you explain how that is? Like with an example?
Math is exactly like English. It’s a language. It’s an abstraction to describe something. Ambiguity exists in math and in English. It impacts the validity of a statement. Hell the word statement is used in math and English for a reason.
Can you explain how that is? Like with an example?
I’m not sure what you’re asking about. Explain what with an example?
Math is exactly like English. It’s a language
No it isn’t. It’s a tool for calculating things, with syntax rules. We even have rules around how to say it when speaking.
It’s an abstraction to describe something
And that something is the Laws of the Universe. 1+1=2, F=ma, etc.
Hell the word statement is used in math and English for a reason
You won’t find the word “statement” used in Maths textbooks. I’m guessing you’re referring to Expressions.
Oh my god now this is going to be Lemmy’s top thread for 6 months, isn’t it?
Btw, yeah I’m with you on this, you just need to know the priorities and you’re good, because the order doesn’t matter for operations with the same priority
Except it does matter. I left some examples for another post with multiplication and division, I’ll give you some addition and subtraction to see order matter with those operations as well.
Let’s take:
1 + 2 - 3 + 4Addition first:
(1 + 2) - (3 + 4)
3 - 7 = -4Subtraction first:
1 + (2 - 3) + 4
1 + (-1) + 4 = 4Right to left:
1 + (2 - (3 + 4))
1 + (2 - 7)
1 + (-5) = -4Left to right:
((1 + 2) - 3) + 4
(3 - 3) + 4 = 4Edit: You can argue that, for example, the addition first could be
(1 + 2) + (-3 + 4)in which case it does end up as 4, but in my opinion that’s another ambiguous case.Oh, but of course the statement changes if you add parentheses. Basically, you’re changing the effective numbers that are being used, because the parentheses act as containers with a given value (you even showed the effective numbers in your examples).
Get this : + 1 - 1 + 1 - 1 + 1 - 1 + 1
You can change the result several times by choosing where you want to put the parentheses. However, the order of operations of same priority inside a container (parentheses) does not change the resulting value of the container.
In the example, there were no parentheses, so no ambiguity (there wouldn’t be any ambiguity with parentheses either, the correct way of calculating would just change), and I don’t think you can add “ambiguity” by adding parentheses — you’re just changing the effective expression to be evaluated.
By the way, this is the reason why I absolutely overuse parentheses in my engineering code. It can be redundant, but at least I am SURE that it is going to follow the order that I wanted.
Oh, but of course the statement changes if you add parentheses
It sure does, but they don’t seem to understand that.
Except it does matter
No it doesn’t. You disobeying the rules and getting lots of wrong answers in your examples doesn’t change that.
I left some examples for another post with multiplication and division
Which you did wrong.
I’ll give you some addition and subtraction to see order matter with those operations as well
And I’ll show you it doesn’t matter when you do it correctly
Subtraction first: 1 + (2 - 3) + 4 1 + (-1) + 4 = 4
Nope. Right answer for wrong reason - you only co-incidentally got the answer right. -3+1+2+4=-3+7=4
Right to left: 1 + (2 - (3 + 4)) 1 + (2 - 7) 1 + (-5) = -4
Nope. 4-3+2+1=1+2+1=3+1=4
Edit: You can argue that, for example, the addition first could be (1 + 2) + (-3 + 4)
Or you could just do it correctly in the first place, always obeying Left Associativity and never adding Brackets
in my opinion that’s another ambiguous case
There aren’t ANY ambiguous cases. In every case it’s equal to 4. If you didn’t get 4, then you made a mistake and got a wrong answer.
Another common issue is thinking “parentheses go first” and then beginning by solving the operation beside them (mostly multiplication). The point being that what’s inside the parentheses goes first, not what’s beside them.
Another common issue is thinking “parentheses go first”
There’s no “think” - it’s an absolute rule.
then beginning by solving the operation beside them
a(b) isn’t an operation - it’s a Product. a(b)=(axb) per The Distributive Law.
(mostly multiplication)
NOT Multiplication, a Product/Term.
The point being that what’s inside the parentheses goes first, not what’s beside them
Nope, it’s the WHOLE Bracketed Term. a/bxc=ac/b, but a/b( c )=a/(bxc). Inside is only a “rule” in Elementary School, when there isn’t ANYTHING next to them (students aren’t taught this until High School, in Algebra), and it’s not even really a rule then, it’s just that there isn’t anything ELSE involved in the Brackets step than what is inside (since they’re never given anything on the outside).
Yeah and I’m tired of pretending it’s not!
"Hey, this is Presh Talwalkar.
discussion of a brief history of this viral math problem, followed by explanations of common incorrect answers. Finally followed by brief discussion on the order of operations, concluding in a final example that ultimately equals 11And that’s the answer. Thank you so much for making us one of the best communities on YouTube, where we solve the world’s problems, one video at a time."
Hey, this is Presh Talwalkar
Person who has forgotten about The Distributive Law and lied about 1917.
Discussion of a brief history of this viral math problem
Including lying about 1917
Ultimately followed by brief discussion on the order of operations
But forgets about Terms and The Distributive Law.
And that’s the answer
Now watch his other ones, where he screws it up royally. Dude has no idea how to handle brackets. Should be avoided at all costs.
I’ve seen many of his videos and haven’t noticed any obvious errors. Could you please link to the specific video(s) that you are referencing in regards to errors he has made, especially those related to the distributive law and what you reference to as “1917,” as well as any explanation as to what is incorrect/misleading/lying?
I’ve seen many of his videos and haven’t noticed any obvious errors.
He makes mistakes every time there’s Brackets with a Coefficient. He always does a(b)=axb, instead of a(b)=(axb), hence wrong every time it follows a division.
what you reference to as “1917,”
No, he calls it that, though sometimes he also tries to claim it’s an article (it isn’t - it was a letter) - he never refers to Lennes by name. He also ignores what it actually says, and in fact disobeys it (the rule proposed by Lennes was to do all multiplication first, and yet he proceeds to do the division first, hence wrong answer, even though he just claimed that 1917 is the current rule).
Here’s a thread about Lennes’ 1917 letter, including a link to an archived copy of it.
Here’s where Presh Talwalker lied about 1917
Here’s a thread about The Distributive Law
Here’s where Presh Talwalker disobeyed The Distributive Law (one of many times) (he does 2x3 instead of (2x3), hence gets the wrong answer). What he says is the “historical” rule in “some” textbooks, is still the rule and is used in all textbooks, he just never looked in any!
Note that, as far as I can tell, he doesn’t even have any Maths qualifications. He keeps saying “I studied Maths at Harvard”, and yet I can find no evidence whatsoever of what qualifications he has - I suspect he dropped out, hence why he keeps saying “I studied…”. In one video he even claimed his answer was right because Google said so. I’m not kidding! He’s a snake oil salesman, making money from spreading disinformation on Youtube - avoid at all cost. There are many freely-available Maths textbooks on the Internet Archive if you want to find proof of the truth (some of which have been quoted in the aforementioned thread).
Thank you very much for the detailed response! Very informative and interesting.
So if it’s not really an event
And it’s not really a math problem
What the hell is it??
Entertainment.
The only thing that will remain on yt anyway after AI has taken over the content generation and we can trust no “creator” anymore.
Engagement bait
I’m sure we’re all geniuses here, but just in case…
Please excuse my dear aunt Sally.
Parenthesis, exponents, multiplication, division, addition, subtraction.
Why? Because a bunch of dead Greeks say so!
3x3-3÷3+3
(3x3)-(3÷3)+3
9-1+3
8+3
11
Cool, except you just said
… Division, addition, subtraction.
And then you performed:
= 9-1+3
= 8+3
= 11When you should have done…
= 9-1+3
= 9-4
= 5Either dear Aunt Sally needs to check her work, or I do.
Multiplication and Division, and Addition and Subtraction are executed at the same level and done in left to right order.
And how is Aunt Sally going to learn if you don’t say that from the start?
Because it’s just a mnemonic to remember what the order of operations is, not like… What the order of operations is, which you should know already if you know the mnemonic.
Because it’s the only other thing about that system at all. OP wasn’t teaching, just showing what that system does. If you looked for a source that explains it you’d be told
For the programmers: operator precedence.
Not a genius. But if subtraction is last, why isn’t it 9-4?
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Addition/subtraction work out the same regardless of how you order the operations. If you do subtraction last you start with the original:
9-1+3
and you are adding 3 to the result of (9-1). Since you are trying to perform it before the (9-1) operation is carried out, you can add 3 to the 9:
12-1 = 11
or you can add three to the -1 and get:
9+2 = 11
You only end up with 9-4 if you were subtracting 3 rather than adding three. It all becomes more obvious if you read the original as:
9 + (-1) + 3
Because its not really “1 plus 3”, its negative 1 plus 3 which is two. I know it seems a little weird but the minus sign is " tied" to the thing following it.
Parenthesis, exponents, multiplication, division, addition, subtraction.
should actually be
Parenthesis, exponents, (multiplication and division), (addition and subtraction).
Addition and subtraction are given the same priority, and are done in the same step, from left to right.
It’s not a great system of notation, it could be made far clearer (and parenthesis allow you to make it as clear as you like), but it’s essentially the universal standard now and it’s what we’re stuck with.
No, it should simply be “Parenthesis, exponents, multiplication, addition.”
A division is defined as a multiplication, and a substraction is defined as an addition.
I am so confused everytime I see people arguing about this, as this is basic real number arithmetics that every kid in my country learns at 12 yo, when moving on from the simplified version you learn in elementary school.
A division is defined as a multiplication
No it isn’t. Multiplication is defined as repeated addition. Division isn’t repeated subtraction. They just happen to have opposite effects if you treat the quotient as being the result of dividing.
Yes, it is. The division of a by b in the set of real numbers and the set of rational numbers (which are, de facto, the default sets used in most professions) is defined as the multiplication of a by the multiplicative inverse of b. Alternative definitions are also based on a multiplication.
That’s why divisions are called an auxilliary operation.
Yes, it is
No it isn’t.
The division of a by b in the set of real numbers and the set of rational numbers (which are, de facto, the default sets used in most professions) is defined as the multiplication of a by the multiplicative inverse of b
No it isn’t. The Quotient is defined as the number obtained when you divide the Dividend by the Divisor. Here it is straight out of Euler…
Alternative definitions are also based on a multiplication
Emphasis on “alternative”, not actual.
No it isn’t.
Yes, it is.
No it isn’t. The Quotient is defined as the number obtained when you divide the Dividend by the Divisor. Here it is straight out of Euler…
I’m defining the division operation, not the quotient. Yes, the quotient is obtained by dividing… Now define dividing.
Emphasis on “alternative”, not actual.
The actual is the one I gave. I did not give the alternative definitions. That’s why I said they are also defined based on a multiplication, implying the non-alternative one (understand, the actual one) was the one I gave.
Feel free to send your entire Euler document rather than screenshotting the one part you thought makes you right.
Note, by the way, that Euler isn’t the only mathematician who contributed to the modern definitions in algebra and arithmetics.
You want PEMA with knowledge of what is defined, when people can’t even understand PEMDAS. You wish for too much.
I’m just confused as to how that is not common knowledge. The country I speak of is France, and we’re not exactly known for our excellent maths education.
I hate most math eduction because it’s all about memorizing formulas and rules, and then memorizing exceptions. The user above’s system is easier to learn, because there’s no exceptions or weirdness. You just learn the rule that division is multiplication and subtraction is addition. They’re just written in a different notation. It’s simpler, not more difficult. It just requires being educated on it. Yes, it’s harder if you weren’t obviously, as is everything you weren’t educated on.
That’s because they aren’t teaching math. They’re teaching “tricks” to solve equations easier, which can lead to more confusion.
Like the PEMDAS thing that’s being discussed here. There’s no such thing as “order of operations” in math, but it’s easier to teach by assuming that there is.
they aren’t teaching math.
Yes we are. Adults forgetting it is another matter altogether.
There’s no such thing as “order of operations” in math
Yes there is! 😂
Do you think I’m wrong?
No, I know you’re wrong.
If so, why?
If you don’t solve binary operators before unary operators you get wrong answers. 2+3x4=14, not 20. 3x4=3+3+3+3 by definition
I guess remembering grade school order of operation means you’re a guinus now? Bar has gotten pretty low…
And it will go even lower as people start relying mpre on AI…
That’s the point.
Set the bar low, but just high enough that tons of people still trip over it.
Sit back and enjoy the comment wars.
The people who are confident but wrong are too proud to admit they were wrong even if they realize it, and comment angrily.
The people who are right and know why, comment for corrections and some to show off how S-M-R-T they are.
The people who are wrong but willing to accept that just have their realization and probably don’t think about it again. So do the people who don’t know and/or care.
But those first two groups will keep the post going in both shares and comments, because “look at all these wrong people”
It’s all designed to boost engagement.
I like the version where these problems are made purposefully ambiguous so people will fight over it and raise the level of interaction
I like the version where these problems are made purposefully ambiguous
None of them are ambiguous. They all have only 1 correct answer, just like this one only has 1 correct answer. They all test if people remember the order of operations rules. Those who got it wrong, don’t.
Lmao here we go
This right here is exactly why it’s been so popular for so long.
G U I N U S.
I know it’s probably a typo, but I’m enjoying it.
I would like to say it was on purpose but it was not :( I might do math, spelling is not my forte.
It’s jeenyus you moran!
All I can envision with that alternative is Whoopi Goldberg with a very fanciful hat serving drinks in space.
Why? Because a bunch of dead Greeks say so!
The Greeks certainly didn’t come up with PEMDAS. US teachers too lazy to teach kids actual maths did. And that’s before taking into account that the Greeks didn’t come up with Algebra.
US teachers too lazy to teach kids actual maths did.
What’s lazy about learning PEMDAS? And what’s the non-lazy/superior way?
I’m a BEDMAS man myself
What’s lazy about learning PEMDAS?
Nothing. Only people who don’t know what they’re talking about say that.
Learning the actual algebraic laws, instead of an order of operations to mechanically replicate. PEMDAS might get you through a standardised test but does not convey any understanding, it’s like knowing that you need to press a button to call the elevator but not understand what elevators are for.
Though “lazy teachers” might actually be a bit too charitable a take given the literacy rates of college graduates mastering in English. They very well might not understand basic maths themselves, thinking it’s all about a set of mechanical operations.
just say you like the smell of your own farts, it would be less text for us to read for the same result
This guy is the the guy posting the answer and then spending hours fighting the idiots who got it wrong on Facebook.
Nerd.
x/0 is the set {+inf,-inf}, fite me IRL.
Is it also lazy to learn Roy G. Biv to know the color spectrum instead of learning all the physics and optical properties behind that?
Or My Very Elderly Mother Just Served Us Nine Pickles to know the planets instead of learning orbital dynamics and astrophysics?
Christ man, it’s a mnemonic device for elementary schoolers.
Those two things are memorisation tasks. Maths is not about memorisation.
You are not supposed to remember that the area of a triangle is
a * h / 2, you’re supposed to understand why it’s the case. You’re supposed to be able to show that any triangle that can possibly exist is half the area of the rectangle it’s stuck in: Start with the trivial case (right-angled triangle), then move on to more complicated cases. If you’ve understood that once, there is no reason to remember anything because you can derive the formula at a moment’s notice.All maths can be understood and derived like that. The names of the colours, their ordering, the names of the planets and how they’re ordered, they’re arbitrary, they have no rhyme or reason, they need to be memorised if you want to recall them. Maths doesn’t, instead it dies when you apply memorisation.
Ein Anfänger (der) Gitarre Hat Elan. There, that’s the Guitar strings in German. Why do I know that? Because my music theory knowledge sucks. I can’t apply it, music is all vibes to me but I still need a way to match the strings to what the tuner is displaying. You should never learn music theory from me, just as you shouldn’t learn maths from a teacher who can’t prove
a * h / 2, or thinks it’s unimportant whether you can prove it.What fundamental property of the universe says that
6 + 4 / 2 is 8 instead of 5?
Nothing. And that’s why people don’t write equations like that: You either see
4 6 + --- 2or
6 + 4 ------- 2If you wrote
6 + 4 / 2in a paper you’d get reviewers complaining that it’s ambiguous, if you want it to be on one line write(6+4) / 2or6 + (4/2)or6 + ⁴⁄₂or even½(6 + 4)Working mathematicians never came up with PEMDAS, which disambiguates it without parenthesis, US teachers did. Noone else does it that way because it does not, in the slightest, aid readability.6 + 4 / 2 is 8 instead of 5?
The fundamental property of Maths that you have to solve binary operators before unary operators or you end up with wrong answers.
Maths is not about memorisation
It is for ROTE learners.
You are not supposed to remember that the area of a triangle is a * h / 2
Yes you are. A lot of students get the wrong answer when they forget the half.
you’re supposed to understand why it’s the case
Constructivist learners can do so, ROTE learners it doesn’t matter. As long as they all know how to do Maths it doesn’t matter if they understand it or not.
You’re supposed to be able to show that any triangle that can possibly exist is half the area of the rectangle it’s stuck in
No they’re not.
If you’ve understood that once, there is no reason to remember anything because you can derive the formula at a moment’s notice.
And if you haven’t understood it then there is a reason to remember it.
you can derive the formula at a moment’s notice
Students aren’t expected to be able to do that.
All maths can be understood and derived like that
It can be by Constructivist learners, not ROTE learners.
The names of the colours, their ordering, the names of the planets and how they’re ordered, they’re arbitrary
No they’re not. Colours are in spectrum order, the planets are in order from the sun.
Maths doesn’t, instead it dies when you apply memorisation
A very substantial chunk of the population does just fine with having memorised Maths.
You might be smart, but you’re still wrong about the importance of order of operations; especially in algebra.
As far as teachers go, you’re being a dick by generalizing all (US) teachers are lazy and do not understand math.
Pro tip: opinions are like assholes; you too have one, and yes it too stinks.
You might be smart
Smart-arse more like. A serial troll who doesn’t actually know what they’re talking about.
The “why” goes a little further than that.
In actuality, it’s because of fundamental properties of operations
- Commutation
a + b = b + a
a×b = b×a
- Association
(a + b) + c = a + (b + c)
(a×b)×c = a×(b×c)
- Identity
a + 0 = a
a×1 = a
If you know that, then PEMDAS and such are useless because they’re derived from those properties but do not fully encompass them.
Eg.
3×2×(2+2) = 3×(4+4) = 12+12 = 24
This is a correct solution that is improper if you’re strictly adhering to PEMDAS rule as I’ve done multiplication before parenthesis from right to left.
I could even go completely out of order by doing 3×2×(2+2) = 2×(6+6) and it will still be correct
Anyone on Facebook that attempts to answer this or engage within its comments has already failed the test.
Anyone on Facebook
that attempts to answer this or engage within its commentshas already failed the test.
I was good at math and it was one of my favorite core subjects in school, so I know I’m a weirdo but… I never understood how people couldn’t understand basic PEMDAS/BEDMAS/Whatever-the-fuck-your-country-calls-it.
Obviously these problems are shitty engagement bait because they don’t use parentheses, but still, seeing people fuck up the fact that Multiplication AND Division occur at the same time, and then the next step is Addition AND Subtraction just stupefies me.
Like, did you sleep through 4 years of elementary school to miss that fact??? Even in middle school pre-algebra teachers still did PEMDAS refreshers. I get that once I get out of college I’m probably gonna forget half the pre-calc shit I learned because I won’t need it, and I’m not being drilled on it everyday like people in school are, but PEMDAS is a fundamental and basic daily life skill that everyone should know…
I really wish we gave a fuck about US education.
I never understood how people couldn’t understand basic PEMDAS/BEDMAS/Whatever-the-fuck-your-country-calls-it.
There’s no “whatever-the-fuck-your-country-calls-it”, the US is the only country using it, and only up to high school. At least I’m not seeing any papers coming out of the US relying on it so at some point they’re dropping it and do what everyone else is doing: Write equations such that you don’t need a left-to-right rule to disambiguate things. Also, using multiplication by juxtaposition (2x + 4x2).
There’s no “whatever-the-fuck-your-country-calls-it”
Yes there is. BEDMAS, BODMAS, and BIDMAS
the US is the only country using it
No they’re not.
at some point they’re dropping it
No, at no point do the order of operations rules ever get dropped
using multiplication by juxtaposition (2x + 4x2)
They’re called Terms/Products.
I was bad at math, but I still managed to get through precal and still remember PEMDAS
For me it’s the arguments when there is a parentheses but no operator (otherwise known as implied multiplication) in these baits e.g. 15 + 2(4 - 2)
If you don’t know operator orders I have given up long ago, but I have seen a few lengthy discussions about this
Oh yeah, that’s a fun one.
Where I live, this would be considered juxtaposition, at least by uni professors and scientific community, so 2(4-2) isn’t the same as 2×(4-2), even though on their own they’re equal.
This way, equations such as 15/2(4-2) end up with a definite solution.
So,
15/2(4-2) = 3.75
While
15/2×(4-2) = 15
Usually, however, it is obvious even without assuming juxtaposition because you can look at previous operations. Not to mention that it’s most common with variables (Eg. “2x/3y”).
Where I live, this would be considered juxtaposition
Not just where you live, everywhere, in Maths textbooks. Adults forgetting the rules (and unqualified U.S. teachers not teaching what’s in the textbooks) is another matter altogether.
For me it’s the arguments when there is a parentheses but no operator (otherwise known as implied multiplication)
No, it’s known as Factorised Terms/Products, solved via The Distributive Law, a(b+c)=(ab+ac). “implied multiplication” is a made up rule by people who have forgotten the actual rules, and often they get it wrong (because, having wrongly called it “multiplication”, they then wrongly give it the precedence of multiplication, not brackets).
Arguing about maths is like dancing to architecture.
Hey, some architecture is asking for it like Stonehenge
