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
this post was submitted on 31 May 2025
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A fake Facebook event disguised as a math problem has been one of its top posts for 6 months
(www.engadget.com)
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
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.
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(1 replies)
For the programmers: operator precedence.
Not a genius. But if subtraction is last, why isn't it 9-4?
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.
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(5 replies)
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.
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
It's multiplication or division from left to right followed by addition or subtraction, also from left to right.
That's where a lot of people fuck up.
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
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(16 replies)
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
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Boomers and Xgens need to prove, that they remember basic school math in FB lmao.
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 first rule of gen-x is you don't talk about gen-x!
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.
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Gen xers? Don't irk them. They're not noticing you right now.
Very independent, and cranky generation.
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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 was bad at math, but I still managed to get through precal and still remember PEMDAS
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(3 replies)
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 comments~~ has already failed the test.
question: is there something more than the expression evaluating to 11?
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(3 replies)
"Hey, this is Presh Talwalkar.
Discussion of a brief history of this viral math problem, followed by explanations of common incorrect answers. Ultimately followed by brief discussion on the order of operations, concluding in a final example that equals 11
And 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."
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.
So order of operations is hard?
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) 😄
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Arguing about maths is like dancing to architecture.
Hey, some architecture is asking for it like Stonehenge
What's the scam?
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 🙏
11
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.
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