|
On April 08 2011 11:13 Zeke50100 wrote:Show nested quote +On April 08 2011 11:11 jalstar wrote:On April 08 2011 11:10 Zeke50100 wrote:On April 08 2011 11:08 jalstar wrote:On April 08 2011 11:07 Zeke50100 wrote:On April 08 2011 11:06 jtan wrote:
There also seems to be some different use of the word ambigous.
The expression 1/x*y is unambigious in the strict computer-sience sense, but like I said, it's ambigious in the sense that a lot of people interpret it differently, you can't really argue against that. Lack of knowledge does not mean ambiguous. Are you really trying to argue that hundreds of people don't know order of operations, or am I missing something? Yes. Hundreds of people (those who have bothered to reply, anyway, which is indicative of response bias in the first place) just don't know their stuff. You can't be serious. I just refuse to believe you're serious. You really can't see how the problem is a trick without assuming complete lack of order of operations knowledge? What the fuck? I never said a complete lack of knowledge. You might want to look up what knowledge means. Somebody's ignorance of the fact that you do not, indeed, multiply 2 by 9+3 before proceeding with the rest of the simplification is a lack of knowledge.
But everyone. knows. that. The problem initially looks like you multiply 2 by 9+3 first because of bad notation, but being confused by bad notation is not the same thing as not knowing what the notation means.
|
On April 08 2011 11:04 jalstar wrote:Show nested quote +On April 08 2011 11:02 space_yes wrote:
You'll never see 1/(2x) written as 1/2x in any published mathematical text b/c 1) formatting and 2) order of operations. I agree the question is tricky but that doesn't make it ambiguous. If you got the first question right and you apply the same rules to the second question you should also get it right. If you got it wrong you used different rules for each question. And you wouldn't see (48/2)(9+3) written as 48/2(9+3) with the exception of trick questions in the exercises.
![[image loading]](http://i55.tinypic.com/332w3sn.jpg)
Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations..
..and people do it incorrectly so they get it wrong 
|
On April 08 2011 11:14 jalstar wrote:Show nested quote +On April 08 2011 11:13 Zeke50100 wrote:On April 08 2011 11:11 jalstar wrote:On April 08 2011 11:10 Zeke50100 wrote:On April 08 2011 11:08 jalstar wrote:On April 08 2011 11:07 Zeke50100 wrote:On April 08 2011 11:06 jtan wrote:
There also seems to be some different use of the word ambigous.
The expression 1/x*y is unambigious in the strict computer-sience sense, but like I said, it's ambigious in the sense that a lot of people interpret it differently, you can't really argue against that. Lack of knowledge does not mean ambiguous. Are you really trying to argue that hundreds of people don't know order of operations, or am I missing something? Yes. Hundreds of people (those who have bothered to reply, anyway, which is indicative of response bias in the first place) just don't know their stuff. You can't be serious. I just refuse to believe you're serious. You really can't see how the problem is a trick without assuming complete lack of order of operations knowledge? What the fuck? I never said a complete lack of knowledge. You might want to look up what knowledge means. Somebody's ignorance of the fact that you do not, indeed, multiply 2 by 9+3 before proceeding with the rest of the simplification is a lack of knowledge. But everyone. knows. that. The problem initially looks like you multiply 2 by 9+3 first because of bad notation, but being confused by bad notation is not the same thing as not knowing what the notation means.
It's not bad notation. Just because somebody is used to a different notation doesn't mean they should not be expected to know the one presented to them. It's not confusing at all if you just know your stuff and think it through.
|
On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations..
Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it.
|
On April 08 2011 11:13 Zeke50100 wrote:Show nested quote +On April 08 2011 11:11 jalstar wrote:On April 08 2011 11:10 Zeke50100 wrote:On April 08 2011 11:08 jalstar wrote:On April 08 2011 11:07 Zeke50100 wrote:On April 08 2011 11:06 jtan wrote:
There also seems to be some different use of the word ambigous.
The expression 1/x*y is unambigious in the strict computer-sience sense, but like I said, it's ambigious in the sense that a lot of people interpret it differently, you can't really argue against that. Lack of knowledge does not mean ambiguous. Are you really trying to argue that hundreds of people don't know order of operations, or am I missing something? Yes. Hundreds of people (those who have bothered to reply, anyway, which is indicative of response bias in the first place) just don't know their stuff. You can't be serious. I just refuse to believe you're serious. You really can't see how the problem is a trick without assuming complete lack of order of operations knowledge? What the fuck? I never said a complete lack of knowledge. You might want to look up what knowledge means. Somebody's ignorance of the fact that you do not, indeed, multiply 2 by 9+3 before proceeding with the rest of the simplification is a lack of knowledge.
But that is not why people got the question wrong. They got it wrong because they assumed that 2(9+3) is being used as a single unit which it often is in a mathematical setting. Nobody was lacking the knowledge of order of operations as you're claiming. Face it, by definition the question is ambiguous. I'll post the definition again in case you missed it:
"Ambiguity is a term used in writing and math, and under conditions where information can be understood or interpreted in more than one way..."
People "interpreted" the 2(9+3) to be one unit it can also be interpreted as not being one unit. There are two ways to interpret it. Two is more that one. It is ambiguous. Clear?
I don't think you have the "knowledge" of what ambiguity is.
|
On April 08 2011 11:16 Zeke50100 wrote:Show nested quote +On April 08 2011 11:14 jalstar wrote:On April 08 2011 11:13 Zeke50100 wrote:On April 08 2011 11:11 jalstar wrote:On April 08 2011 11:10 Zeke50100 wrote:On April 08 2011 11:08 jalstar wrote:On April 08 2011 11:07 Zeke50100 wrote:On April 08 2011 11:06 jtan wrote:
There also seems to be some different use of the word ambigous.
The expression 1/x*y is unambigious in the strict computer-sience sense, but like I said, it's ambigious in the sense that a lot of people interpret it differently, you can't really argue against that. Lack of knowledge does not mean ambiguous. Are you really trying to argue that hundreds of people don't know order of operations, or am I missing something? Yes. Hundreds of people (those who have bothered to reply, anyway, which is indicative of response bias in the first place) just don't know their stuff. You can't be serious. I just refuse to believe you're serious. You really can't see how the problem is a trick without assuming complete lack of order of operations knowledge? What the fuck? I never said a complete lack of knowledge. You might want to look up what knowledge means. Somebody's ignorance of the fact that you do not, indeed, multiply 2 by 9+3 before proceeding with the rest of the simplification is a lack of knowledge. But everyone. knows. that. The problem initially looks like you multiply 2 by 9+3 first because of bad notation, but being confused by bad notation is not the same thing as not knowing what the notation means. It's not bad notation. Just because somebody is used to a different notation doesn't mean they should not be expected to know the one presented to them. It's not confusing at all if you just know your stuff and think it through.
Drawing an ugly painting of a car is worse than drawing a nice painting of a car, even though they both clearly have 4 wheels. I shouldn't have to think through a basic problem if it's written well.
|
On April 08 2011 11:16 jalstar wrote:Show nested quote +On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations.. Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it.
I am now going to assume you don't know what ambiguity is. "Confusing" is not ambiguity if the cause of the confusion is ignorance (or even just not reading correctly).
On April 08 2011 11:16 MadVillain wrote:Show nested quote +On April 08 2011 11:13 Zeke50100 wrote:On April 08 2011 11:11 jalstar wrote:On April 08 2011 11:10 Zeke50100 wrote:On April 08 2011 11:08 jalstar wrote:On April 08 2011 11:07 Zeke50100 wrote:On April 08 2011 11:06 jtan wrote:
There also seems to be some different use of the word ambigous.
The expression 1/x*y is unambigious in the strict computer-sience sense, but like I said, it's ambigious in the sense that a lot of people interpret it differently, you can't really argue against that. Lack of knowledge does not mean ambiguous. Are you really trying to argue that hundreds of people don't know order of operations, or am I missing something? Yes. Hundreds of people (those who have bothered to reply, anyway, which is indicative of response bias in the first place) just don't know their stuff. You can't be serious. I just refuse to believe you're serious. You really can't see how the problem is a trick without assuming complete lack of order of operations knowledge? What the fuck? I never said a complete lack of knowledge. You might want to look up what knowledge means. Somebody's ignorance of the fact that you do not, indeed, multiply 2 by 9+3 before proceeding with the rest of the simplification is a lack of knowledge. But that is not why people got the question wrong. They got it wrong because they assumed that 2(9+3) is being used as a single unit which it often is in a mathematical setting. Nobody was lacking the knowledge of order of operations as you're claiming. Face it, by definition the question is ambiguous. I'll post the definition again in case you missed it: "Ambiguity is a term used in writing and math, and under conditions where information can be understood or interpreted in more than one way..." People "interpreted" the 2(9+3) to be one unit it can also be interpreted as not being one unit. There are two ways to interpret it. Two is more that one. It is ambiguous. Clear? I don't think you have the "knowledge" of what ambiguity is.
The definition of ambiguity you used is a vague, broad definition that only serves to include pretty much anything you want.
I interpret 2+2 to equal 5. To hell with it, it's an ambiguous question.
2(9+3) isn't a single term. Even if it is, that would mean 288 is simply wrong, not that the question itself is ambiguous.
|
On April 08 2011 11:17 Zeke50100 wrote:Show nested quote +On April 08 2011 11:16 jalstar wrote:On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations.. Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it. I am now going to assume you don't know what ambiguity is. "Confusing" is not ambiguity if the cause of the confusion is ignorance (or even just not reading correctly).
If your brain doesn't read it correctly immediately then it's poorly written. Not much else to say there.
|
When i see a divide sign, i interpret it as thing on the left over thing on the right
So I ended up with
_48_
2(9+3)
Which ends with the answer 2
|
On April 08 2011 11:16 Zeke50100 wrote:Show nested quote +On April 08 2011 11:14 jalstar wrote:On April 08 2011 11:13 Zeke50100 wrote:On April 08 2011 11:11 jalstar wrote:On April 08 2011 11:10 Zeke50100 wrote:On April 08 2011 11:08 jalstar wrote:On April 08 2011 11:07 Zeke50100 wrote:On April 08 2011 11:06 jtan wrote:
There also seems to be some different use of the word ambigous.
The expression 1/x*y is unambigious in the strict computer-sience sense, but like I said, it's ambigious in the sense that a lot of people interpret it differently, you can't really argue against that. Lack of knowledge does not mean ambiguous. Are you really trying to argue that hundreds of people don't know order of operations, or am I missing something? Yes. Hundreds of people (those who have bothered to reply, anyway, which is indicative of response bias in the first place) just don't know their stuff. You can't be serious. I just refuse to believe you're serious. You really can't see how the problem is a trick without assuming complete lack of order of operations knowledge? What the fuck? I never said a complete lack of knowledge. You might want to look up what knowledge means. Somebody's ignorance of the fact that you do not, indeed, multiply 2 by 9+3 before proceeding with the rest of the simplification is a lack of knowledge. But everyone. knows. that. The problem initially looks like you multiply 2 by 9+3 first because of bad notation, but being confused by bad notation is not the same thing as not knowing what the notation means. It's not bad notation. Just because somebody is used to a different notation doesn't mean they should not be expected to know the one presented to them. It's not confusing at all if you just know your stuff and think it through.
It's pretty much always considered bad notation not to group things with parenthesis to distinguish terms. This doesn't make it necessarily wrong, but definitely bad. In math one typically wants what they mean to be clear and distinct, which means grouping terms together.
|
On April 08 2011 11:17 Zeke50100 wrote:Show nested quote +On April 08 2011 11:16 jalstar wrote:On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations.. Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it. I am now going to assume you don't know what ambiguity is. "Confusing" is not ambiguity if the cause of the confusion is ignorance (or even just not reading correctly).
The cause of the confusion wasn't ignorance.
|
On April 08 2011 11:16 jalstar wrote:Show nested quote +On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations.. Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it.
It's not bad notation. Most discussion boards don't natively support any kind of mathematical formatting. For many of my class discussion boards the syntax of the expression in the poll is commonly used and nobody is qqing b/c of ambiguity. Though I am an applied math major; I would guess this question generally tricks non-engineering people.
|
On April 08 2011 11:05 Zeke50100 wrote:Show nested quote +On April 08 2011 11:03 jtan wrote:On April 08 2011 10:49 Zeke50100 wrote:On April 08 2011 10:45 jtan wrote:
It is an ambigous expression in the sense that people in fact interpret it differently, as witnessed by the poll.
Having extremely strict rules of "math-grammar" might be good for some purposes, such as teaching high school students how a calculator works, but when communicating mathematical ideas it is often more convenient to use less strict notation and rely on the mutual understanding of the people involved.
For example, if I got an email from a professor containing the expression 1/2x I would be sure he meant 1/(2x) because otherwise he would have written x/2.
In any case, calling people stupid just because they get this wrong is ridiculous. It is a test of grammar-nazism, not of mathematical ability. And if you had the question on a test, you would get it wrong. Rules exist for a reason. It doesn't matter if you rely on "informal" meanings, because you should never assume everybody will follow them, because they are technically wrong (at least when you're limited to single lines of text). Rules exist for a reason you say. The reason is of course to make communication from the writer to the reader as easy as possible. My point is, however, that this is sometimes better achieved with less strictness. Obviously not, otherwise nobody beyond the necessary level of math (which would be almost everybody) would get all of the questions correct. "Easier" doesn't mean " better".
I find it silly to argue against that last statement I made. Did you never come across a text in mathematics which made abuse of notation in order to make the exposition more readable?
|
On April 08 2011 11:18 jalstar wrote:Show nested quote +On April 08 2011 11:17 Zeke50100 wrote:On April 08 2011 11:16 jalstar wrote:On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations.. Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it. I am now going to assume you don't know what ambiguity is. "Confusing" is not ambiguity if the cause of the confusion is ignorance (or even just not reading correctly). If your brain doesn't read it correctly immediately then it's poorly written. Not much else to say there.
I'm sorry that everything in life isn't handed to you on a silver platter. Unfortunately, (2) + (2) is still equal to 4, and is completely unambiguous, no matter what you want to say. "Poorly written" sounds like a euphemism for "yeah, I just don't like it".
|
Nobody is dumb for getting this question wrong. PEMDAS is correct, but the caveat that is often not taught, or quickly forgotten, is that multiplication and division have equal precedence and is done from left to right, as is addition and subtraction.
I only know this because I got a question wrong based on this very fact several years ago in a beginning calculus class. It's just not an issue that comes up very often and nobody who gets it wrong should feel bad. 48 ÷ 2 (9 + 3) is 288. To put it more clearly, it can also be written as (48 ÷ 2) (9 + 3). However, it *cannot* be written as 48 ÷ (2 (9 +3)), which is how many people incorrectly got the answer of 2.
(1/2) * x is the answer to the second question for same reasons.
|
288 i believe (48/2)12=288
|
I'm happy I got it right.
If anything else this proves that Everyone, not just Americans, suck at math. 
|
On April 08 2011 11:20 space_yes wrote:Show nested quote +On April 08 2011 11:16 jalstar wrote:On April 08 2011 11:14 space_yes wrote:Not sure what to tell you. The poll only tricks people b/c the fraction is written on one line instead of being formatted so you have to use order of operations.. Writing it on one line is the trick. It's bad notation and confusing at first glance. That book writes it on two lines, which is the proper way to do it. It's not bad notation. Most discussion boards don't natively support any kind of mathematical formatting. For many of my class discussion boards the syntax of the expression in the poll is commonly used and nobody is qqing b/c of ambiguity. Though I am an applied math major; I would guess this question generally tricks non-engineering people.
I find it difficult to believe you're an applied math major if you're using numbers and basic arithmetic symbols in most of your classes anyway. I haven't used a calculator in over a year myself.
|
On April 08 2011 11:09 shinosai wrote:
Hmm. I got it wrong, but I'm not really bothered by it. My calculus book never had such poor notation. Parenthesis are your friend. I think this thread really just amounts to people being annoyed by bad notation (not necessarily wrong, but bad nonetheless). In the math classes that I took, using parenthesis to make your work clear and concise was mandatory.
That's calculus though.
When you see a problem written in the following you have to ask yourself. What is the problem asking? There are only 3 things. Brackets, division and multiplication. What does this tell you? One of the first things you learned about operations. What you see is what you get. It's poor form to the scholarly eye; however, the shitty form is a good indicator of the lesson is trying to teach in the first place.
There's a good reason why ÷ signs are used less frequently as you climb the mathematical ladder! Grade school math. Order of operations! :O
The fact you guys are saying it's ambiguous should tell you it's an elementary question a youngster would ask.
There is similar shit in writing.
|
On April 08 2011 11:19 abaDURRR wrote:
When i see a divide sign, i interpret it as thing on the left over thing on the right
So I ended up with
_48_
2(9+3)
Which ends with the answer 2
...So, as soon as you see a division sign, you immediately stick EVERYTHING to the right of it in the denominator if it's not offset by parentheses? >.>
|
|
|
|
|
|
EPT
