General Discussion
Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region ForumsI'm not bummed so much by the fact that people cannot solve a simple equation
But by how nasty they get defending their wrong answers, or attacking the people who got it wrong.
For example, there is a posting going around Facebook about how to solve the equation 7+7/7+7x7-7
Many people choose the wrong answer because they don't apply something that was, or should have been, taught back in elementary school - PEMDAS (Parentheses, Exponentiation, Multiplication, Division, Addition, and Subtraction). Instead, they blindly solve left to right.
OK, fine. Math is hard for some people. We need better education to help people with fundamental skills like reading, writing, and arithmetic. And beyond that, we have to accept a certain portion of the population is developmentally disabled. Their brain, due to physical defect or emotional trauma, will never be able to solve mathematic equations.
No, what is really troubling is the name calling that goes on with those threads. We expect, even DEMAND, world peace, yet people don't realize that world peace has to start at the root. Until we have peace between individuals, we won't have a broader peace.
The Straight Story
(48,121 posts)drm604
(16,230 posts)The two are equivalent.
1-Old-Man
(2,667 posts)srican69
(1,426 posts)brackets and everyone will have the same answer.
Coyotl
(15,262 posts)TheMadMonk
(6,187 posts)Working from left to right:
- Brackets/parentheses
- exponent/root
- fractions/multiplication/division
- addition/subtraction
What you mean is use brackets and everyone can be dead lazy and not think at all.
srican69
(1,426 posts)which the operations are entered ..
it's a better idea to idiot proof your expressions rather than be sorry.
TheMadMonk
(6,187 posts)My very first VFD calculator was able to manage the necessary two levels of nesting.
Once upon a time, calculators were tools akin to abacuses and slide rules, their purpose was not to do the whole job, their purpose was to avoid tedious and unnecessary repetition.
The expectation is that the user properly understands the underlying processes.
The expectation is that the user is not a trained monkey punching buttons by rote.
FFS, every single notational shorthand used in mathematics has very simple rules as to where to place all the brackets necessary to recursively unfold a complex arithmetic expression.
If you have to idiot proof your expressions to the extent that you are mindlessly applying TWO FACTOR FUNCTIONS in strict sequence to a series of numbers, you need to shoot the current crop of idiots and look for at least a marginally better class of idiot. Or employ a Von-Neuman machine.
srican69
(1,426 posts)operations and get to the right answer.
HiPointDem
(20,729 posts)it's not like they knew it but it took too much effort to use it, so they didn't....
TheMadMonk
(6,187 posts)HiPointDem
(20,729 posts)hobbit709
(41,694 posts)ret5hd
(20,482 posts)Baitball Blogger
(46,682 posts)hobbit709
(41,694 posts)Worried senior
(1,328 posts)and I don't remember my kids learning it either but then they knew I sucked at math so maybe never brought it up.
I don't have to take my shoes off to count to 10 but this is way over my head.
Bay Boy
(1,689 posts)Or is someone going to make fun of me?
Multiplication and division come before addition and subtraction, then you go left to right.
So 7+7/7+7x7-7 becomes 7+(7/7)+(7x7)-7, which becomes 7+1+49-7. Evaluated left to right, you have 7+1 equals 8, plus 49 equals 57, minus 7 equals 50.
Bay Boy
(1,689 posts)because I didn't even read the problem correctly.
drm604
(16,230 posts)I know this stuff because I program computers for a living so basic arithmetic rules are second nature to me, but in my opinion expressions like this should be written with parenthesis to make it totally clear since most people don't deal with stuff like this on a daily basis.
If I don't use it now and then for spreadsheets either, I'd have gotten lost.
It is easy to lose these skills after years of not using them.
It takes me about a week to re-acquaint myself with some of the math I haven't used in close to 10 years.
Armstead
(47,803 posts)Fix The Stupid
(947 posts)FrodosPet
(5,169 posts).
geek tragedy
(68,868 posts)the equation is essentially a mish-mash of symbols interrupted by the number 7. No competent mathematical modeler would ever write such gibberish.
Without knowing what this number is supposed to calculate assuming PEMDAS (instead of BOMDAS) is just that, an assumption. It would also assume that the writer of the equation didn't know how to properly write their formula to avoid confusion.
drm604
(16,230 posts)They're just mnemonics to help you remember. The ordering of multiplication and division (and addition and subtraction) in the mnemonic doesn't indicate the ordering of those operations. Multiplication and division are on the same level and are evaluated left to right, then addition and subtraction are evaluated left to right.
geek tragedy
(68,868 posts)math is math. If the exact operation to be performed is expressed unclearly in symbolic form, then it's a breakdown in human expression and communication of that math.
drm604
(16,230 posts)but the fact remains that things are often expressed assuming standard precedence rules so people should know those rules.
That said, I recognize that there's a lot of misunderstanding regarding operator precedence. When I write computer code, I always use parenthesis. I do this to make it clear to others reading the code, and because I don't always trust that the compiler/interpreter will evaluate it correctly otherwise.
Most calculators don't obey the rules for obvious reasons.
Orrex
(63,172 posts)It would be like stripping out the spaces and punctuation from a block of text and then laughing your ass off at the poor ignorant fool who pauses in the wrong place.
It's a stupid riddle and a useless tool for assessing intelligence or mathematical ability. I got the right answer, and I still think that it's a dumb trick.
MrYikes
(720 posts)I'll watch Big Bang Theory, get the answer and report back to you.
demwing
(16,916 posts)Parenthesis
Exponents
Multiplication/Division (same level of order, work left to right)
Addition/Subtraction (same level of order, work left to right)
When no parenthesis or exponents exist, move directly to the multiplication and division, solving from left to right:
7/7=1
7*7=49
Now add or subtract, solving from left to right.
kentauros
(29,414 posts)(I don't recall having been taught that particular acronym, although the answer is fifty) I usually look at such things as nothing more than a means to have a little mental play-time or gymnastics. Personally, I'd much rather we taught the various fields with real-world problems. Maybe then people would learn the subjects better.
For example, I learned and retained more about trigonometry when I took Applied Trig in my drafting classes than I'd ever learned in grade school and later in college. Had I taken Applied Calculus before attempting the theory-only class, I might not have failed that one (I didn't take Applied Calculus due to it not being a requirement for most drafting classes.)
I still remember some of the trig formulas thirty years later and know how to apply them. What is the real-world application of the equation "7+7/7+7x7-7" other than for developing mental acuity? Perhaps if the equation had been presented that way, more people might have solved it and then you'd have had fewer bad reactions
Orrex
(63,172 posts)Back in my day, we went with the ol' reliable
"Please Excuse Me, Dear Aunt Sally."
It's gotten me out of more bad scrapes than I care to recount.
kentauros
(29,414 posts)As someone else here pointed out, we learned "order of operations" without needing a mnemonic. And it was all fine and dandy for learning theory, but I'd be hard-pressed to put any of that to practical use today.
And even as Autcad calculates many of our angles and distances for us (in my field) we still need to know surveying well enough to know what we're drawing, and that's almost nothing but trig-based.
Orrex
(63,172 posts)Practically speaking, the great majority of people will never find themselves in a situation where their well-being depends on whether or not they can sort out the order of operations on paper. I haven't used or had any need to use calculus in over twenty years, but to a certain type of person I expect that my ignorance of the subject would be a clear sign of a failing educational system.
Phooey.
kentauros
(29,414 posts)but the biggest thing people need to know first is how to program Excel. Once you know that, you can make it do any math operations. Most of the engineers I've talked with about the use of calculus all said they just used Excel
Of course, with programming, you have a whole new set of operations-order to contend with...
Orrex
(63,172 posts)But engineering is a science-based discipline, ditto for programming, I should think.
I worked in financial services for about eight years, calculating commission payments on multi-billion dollar transactions with complicated rules and exceptions and blah blah blah. I used Excel and Access extensively and got by just fine without ever dredging up my long-dead calculus knowledge.
But that's kind of what I'm getting at: the lack of a specific and semi-esoteric bit of knowledge shouldn't be taken as a sign that someone is dim or uneducated. They may simply have no use for that knowledge daily practical life.
kentauros
(29,414 posts)making one supposedly less than intelligent. Everyone has their strengths, in whatever field. Let's celebrate people for who they are now, and not for what they don't know or can't understand (unless they are doing so willfully...)
Orrex
(63,172 posts)Years ago, when I was an even bigger asshole, I was strongly inclined to look down on people who "only" went to vo-tech or trade schools.
Well who the hell am I? And what the hell is my problem?
Many of them came away with practical and highly technical knowledge that I will never possess, and it took me a long time to recognize their strengths as strengths, rather than dismissing them as weakness simply becuase those people didn't have my "strengths."
Such as the ability to misspell because without batting an eye.
kentauros
(29,414 posts)That is, while they get the commands from the brain to spell "because" properly, our fingers are going "Fuck you! People will be able to figure it out. Eventually."
I don't know what it will take to improve our education system, but the Finnish one sure does seem like one of the better ones to emulate. I would love to see more people in vocational schools, versus listening to their parents (as I did) and trying to get that coveted BA/BS degree when they really aren't capable of or interested in that kind of training. My own BA probably does help on my resume, but my experience is what usually gets me the jobs.
Maeve
(42,271 posts)After 40+ years I can still hear my algebra teacher's voice saying "My Dear Aunt Sally--multiply, divide, add and subtract in THAT ORDER!"
Ah, memory lane...
hunter
(38,302 posts)The trigonometry in drafting and the calculus in physics made everything a whole lot clearer to me.
I'm much better at "seeing" things in my head than manipulating abstract symbols.
The symbol manipulation aspects of education -- simply memorizing "stuff" to be repeated on exams -- is often disconnected from the application, especially in our high schools.
My college physics professor was especially irritated by the quality of the "straight A" students he was getting in his freshman and sophomore classes. His lectures, and the labs he supervised. were fascinating and intense. He was always friendly and approachable and he enjoyed meeting with students during his office hours. But his exams were brutal. There was no way to pass them simply by memorizing stuff. One had to demonstrate a thorough understanding of the material.
For many of my classmates, with high SAT scores and four-point-something grade point averages in high school, it was the first "B" or "C" they'd ever got, maybe even an "F" on the first exam, and it was quite traumatic for them.
kentauros
(29,414 posts)Even in drafting, we had difficult classes, such as structural, where trig was also used to determine stresses on trusses and beams. Yet, the instructors made it fun to figure that stuff out, even if one problem could take fifteen minutes to complete.
Now, one of my best instructors (ancient art history) did give you credit on the essay exams if you managed to successfully BS your way through a question
msanthrope
(37,549 posts)Gormy Cuss
(30,884 posts)I WAS taught to use parentheses for clarity.
nadinbrzezinski
(154,021 posts)But I assure you, that is the first time I have seen that equation presented that way.
I grew up Un another country, so had to first figure out what the hell that was? Yup, taking the sat was all kinds of fun.
Morning Dew
(6,539 posts)The answer is ONE.
kentauros
(29,414 posts)Q. What did the yogi say to the hot dog vendor at the ball game?
A. Make me one with everything!
After the man received his hot dog, he gave the vendor a $20 bill. The vendor just smiled.
The man, infuriated, demanded, "Where is my change?"
The vendor replied, "O, one with everything, change comes from within."
Morning Dew
(6,539 posts)I know someone who will love that one.
kentauros
(29,414 posts)of an Australian reporter telling a version of that joke to the Dalai Lama. He doesn't get the joke, at all, which is funny because then the reporter has to try and explain the joke
Here's the site where I found the text of that joke above, so you can send it to your friend:
http://www.lucid-dreams.com/yoga/yoga-jokes.htm
Morning Dew
(6,539 posts)SheilaT
(23,156 posts)without any parentheses would allow a person to simply perform each operation as it occurs. Or insert the parentheses wherever they want.
kentauros
(29,414 posts)7
--
7
If you just repeat what was originally posted in words, you get this:
seven plus seven divided by seven plus seven times seven minus seven. There is absolutely no hint that there are parentheses anywhere.
proud2BlibKansan
(96,793 posts)even if there aren't any parentheses.
SheilaT
(23,156 posts)seven plus seven. And you give me the answer. The I say, divided by seven, and you give me that answer. And so on. Just writing it out that way is highly ambiguous. Because you can also put in the parentheses like this: (7+7)/7+7 7-7)
Simply writing out a string of numbers and signs isn't necessarily making it clear what should be done. Yes, I understand about order of operations, but the way I was taught it was paying attention to what was inside the parentheses. Without those little marks you have no idea what really should be done in what order.
demwing
(16,916 posts)if there are no exponents, go to the next step in the order of operations - multiplication and division.
There are two equations in that order...7/7 and 7*7. Remember there are no parenthesis or brackets, so no other digits are included in these equations - solve them.
Finally, go to the last step in the order of operations - addition and subtraction.
The entire equation is now in that order, solve left to right.
Recursion
(56,582 posts)I don't blame the non specialists who took it
IdaBriggs
(10,559 posts)http://www.slate.com/articles/health_and_science/science/2013/03/facebook_math_problem_why_pemdas_doesn_t_always_give_a_clear_answer.html
What Is the Answer to That Stupid Math Problem on Facebook?
And why are people so riled up about it?
By Tara Haelle
Perhaps youve seen the problem on Facebook or another forum: 6 ÷ 2(1+2) = ?
Its one of several similar math problems popping up on social networks recently. Perhaps you, too, thought, Duh! Thats easy, and then, as I did, became embroiled in an epically long comment thread while your blood pressure steadily rose because you could not possibly understand why the others doing this problem could not get the right answer.
Perhaps, if youre a nerd like me, or you teach math as I do, you even fell asleep thinking about this problem, baffled and frustrated about why you were unable to convince intelligent, educated friends that your calculation of this deceptively simple problem was accurate.
(snip)
But first, why do we get so riled up about these problems? People dont usually get into fistfights at the bar over arithmetic, but these math threads are spectacularly vitriolic. A couple of factors are at work in these math debates, according to Robert Glenn Howard, a social psychologist at the University of WisconsinMadison who specializes in Internet communication and folklore.
(snip)
So people dig in, not realizing the other reason these debates drag ona mathematical one. We are taught to think of math as an absolute discipline without ambiguity. To an extent, thats true: Two plus two is always four. But while the math itself lacks ambiguity, the way we express that math requires a system of symbolsotherwise known as language. Consider how often people debate grammar. Math has syntax just as language doeswith the same potential for ambiguities. And just as word-based riddles exploit the ambiguities of language, so do these math problems.
(more at link)
Fascinating, well written article. Enjoy it!
Ron Obvious
(6,261 posts)Since they can so easily lead you astray. I remember the order of operations by remembering that operations that have the most impact go first. I think of multiplication as super-addition.
Atman
(31,464 posts)I also understand that it is intentionally ambiguous just to attract hits on someone's Facebook account in order to help them gain revenue via an FB with a huge hit count.
Don't forget to tell the little girl with Down Syndrome that she is really pretty. And remember dial telephones. And give that kid 100,000 likes so his dad will buy him a pony.
WCIL
(343 posts)The elementary school I attended for 3rd-6th grades in the mid '70's was extremely low income and most students couldn't even read. Those that could were pretty much left to read library books all day while the teachers worked with the others. The little math we had was very simple - I was learning the 9 times tables in 6th grade. I had no science or social studies/geography education until junior high school. Back then, you only had to take 2 years of high school math; I had abysmal grades and got out of mathematics as soon as I could. I wish I had better math skills, but I was never given the tools.
Dr. Strange
(25,916 posts)But yes, the value of 7+7/7+7x7-7 is 50.
Cleita
(75,480 posts)that necessary for an equation?
VWolf
(3,944 posts)There is only an expression to simplify.
kudzu22
(1,273 posts)I just assumed the OP meant to add " = x, solve for x" at the end of the arithmetic expression.
Dr. Strange
(25,916 posts)"Find the value of 7+7/7+7x7-7."
That works too.
pipi_k
(21,020 posts)I am a mathematical moron. Can't even solve simple addition/subtraction problems in my head.
If I tried to solve that problem and got the wrong answer, I would definitely NOT get defensive...
LeftInTX
(25,126 posts)(7X7)+(7-7)
Go figure
ChoppinBroccoli
(3,781 posts)But it doesn't surprise me that people can't do math. One thing I learned once I got on the internets years ago was that you could throw most people for a loop simply by SUGGESTING that the contraction for the phrase "you are" is NOT spelled "your." And don't even get me started on there/they're/their. People can't even properly communicate in the language they have spoken their entire lives, and you expect them to be able to do math too?
kentauros
(29,414 posts)most people don't edit their posts before making them, much less reread them. The thing with the Internet is "immediacy". They don't have time to edit or proofread because most people will ignore those mistakes and go for the gist of what they're trying to say.
And then there are those of us for whom our fingers refuse properly obey theyr're mental commands, and you get what I left back their'
LanternWaste
(37,748 posts)"People can't even properly communicate in the language they have spoken their entire lives...?"
Much like beginning a sentence with a conjunction? For example, "But it doesn't surprise me that people can't do math..."
One of the reasons I rarely criticize the writing of others (unless I'm slumming in the proofing department), whether formal or informal, is that I am quite often guilty of the same penned sins myself.
ChoppinBroccoli
(3,781 posts)My college English professor taught me 20 years ago that the rule about beginning sentences with conjunctions had been tossed. It's now perfectly fine to begin a sentence with a conjunction.
Phillip McCleod
(1,837 posts)..and?
HiPointDem
(20,729 posts)Spider Jerusalem
(21,786 posts)7+7/7+7*7-7=7+1+49-7=50
Duer 157099
(17,742 posts)could precipitate a whole thead discussion about order of operation proves your point.
Well done.
TransitJohn
(6,932 posts)How could that be hard?
FrodosPet
(5,169 posts)It can be any of several reasons. Lack of a good educational situation. Perhaps their math teachers were not all that good. Perhaps their classes were full of disruptive kids. Home distraction, sexists telling them "girls can't do math", many other factors.
Some people are developmentally impaired. They may be high functioning, but no matter how many hours you spent tutoring them, their brain will not be able to process math.
And some people are just proudly, deliberately ignorant. Their focus is narrow. They don't see how understanding math affects their lives in a world where all the math is done for them. To them, it is a nerd thing, and they are "too cool".
As a computer technician / network admin, I used to get frustrated by people who bragged about being "computer illiterate". And these were education professionals: teachers and administrators! I never could understand why people who did not have a hunger for gaining knowledge and understanding as well as disseminating it, ever got into education.
RiffRandell
(5,909 posts)I read this post yesterday and couldn't figure it out. I showed it to him this morning and he solved it within seconds.
I had him explain to me how he solved it; I feel stupid.
baldguy
(36,649 posts)in Octal.
FrodosPet
(5,169 posts)in Binary.
OK, I cheated and used the calculator. But if I wasn't in a hurry, I could have solved that conversion in my head (Nerd Alert: Yes, it is true. I did code in machine and 6502/6510 and 8088 assembly language back in the 80's).
tledford
(917 posts)SidDithers
(44,228 posts)It has its own rules and puncutation.
The goal of a math statement, like a statement in any other language, is to clearly and concisely transmit an idea or information.
And, just like a statement in any other language, a poorly constructed math statement conveys an ambiguous message. It's not surprising that the meaning of the math statement in the OP is confusing, and open to different interpretations, because it's written in a way that forces the reader to guess the intention of the writer. Proper punctuation changes the meaning of any math statement, just like it does with a statement in English.
A woman without her man is nothing.
A woman: without her, man is nothing.
Most people would interpret the math statement in the OP the same way, and come up with the answer of 50. But if the writer wanted to absolutely be clear about the message in their math statement, they would have written it with math punctuation that made it obvious what they meant:
Instead of 7+7/7+7x7-7, how about:
Blame the confusion on the writer, not the reader.
Sid
trotsky
(49,533 posts)Let's eat Grandma!
Let's eat, Grandma!
Improper punctuation kills.
SwissTony
(2,560 posts)I was taught BODMAS at school.
Here's a question for you (not you personally, Sid, but for everyone)...logical operators and precedence...
x=1
y=2
z=3
Does the expression
x==1 AND y==2 OR z==6
evaluate to TRUE or FALSE
where "x=1" assigns the value 1 to the variable x and "x==1" returns TRUE if x is indeed equal to 1 and FALSE otherwise? C programmers and Stata users will recognise the double equals operator. Hopefully, it won't confuse people who are neither.
No cranking up Excel, Stata or SAS.
hfojvt
(37,573 posts)"we need better education"
Why? So people can solve meaningless little puzzles?
You just joined the side that thinks they are superior to the side that gets the wrong answers. Try using this method to solve this problem.
"Everybody can be great. Because everybody can serve.
You don't have to have a college degree to serve. You don't have to make your subject and your verb agree to serve. You don't have to know about Plato and Aristotle to serve. You don't have to know Einstein's theory of relativity to serve. You don't have to know the second theory of thermodynamics in physics to serve.
You only need a heart full of grace. A soul generated by love." - Martin Luther King
sibelian
(7,804 posts)JustFiveMoreMinutes
(2,133 posts)DUH.
LOL!
privatename9
(1 post).....most people missed the point altogether and began bantering. *sigh* Thanks for the post
FrodosPet
(5,169 posts)Too many antis, not enough Aunties.
It seems like many people are conservative because it is anti-liberal, and people who are liberal because it is anti-conservative.
Hopefully someday more people will start standing for things than are standing against things.