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funny that the results of the third poll are in opposition to the first one
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I love how mathematicians have been pointing out the potential difference between 2*(9+3) and 2(9+3) for the entire fucking thread, and the preferred response is "third grade math LOL".
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On April 08 2011 10:27 space_yes wrote:This thread is getting ridiculous. I spent 15 minutes writing a well thought-out post then some douchebag only reads the last few sentences then makes an unreasonably dickish and wrong response. There is even some guy arguing that "48/2(9+3)" has no multiplication operator. Soon people will start saying 2 + 2 = 22 b/c there is no universal way to interpret mathematical expressions. Mods please close 
And yet 2 + 2 = 1 in field F3 (or Z3 if you please).
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On April 08 2011 10:37 jalstar wrote:Show nested quote +On April 08 2011 10:35 Zeke50100 wrote:On April 08 2011 10:32 VALERO wrote:On April 08 2011 10:27 jalstar wrote:On April 08 2011 10:25 VALERO wrote:
i've never been more confused in my life
people are not only picking wrong answers to a fifth grade math problem, they're also trying to argue that it's "ambiguous" and that their retard interpretation is right too If you write a problem well then it's clear to see what the right answer is. Even people who got 288 probably second-guessed themselves. the only second guessing i did was determining if this was a real thread and not some elaborate joke Likewise ^_^ To be honest, it's an unfair question to ask somebody if they second-guessed themselves, since you will never just definitively have an answer to something after only thinking about it once. I always "check my work" in case a make a mistake, which I hardly can consider second-guessing at the same level as "Oh wait, but it might actually be...". If you write (48/2)(9+3) you shouldn't have to check your work even. There's literally no room to make a mistake. Of course, you don't get 40 page threads either, but since no one seems to be happy about this thread that might be a good thing.
Oh, it's not that I doubt the process of getting to the answer; it's just that I've been slightly more cautious with my mental math (as in, giving it more than half a second of thought) ever since I answered a test question wrong because I thought 3 + 3 was 9.
Also, you don't need to add in extra parentheses. I can read the way it's written in the OP perfectly fine. Rearranging it into a more comfortable way is a method of preventing error, in itself, which is what "second-guessing" is 
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On April 08 2011 10:39 StarStruck wrote:Show nested quote +On April 08 2011 10:33 sicarii wrote:
how does it feel that those of you who picked 2 would fail a 3rd grade test... Show nested quote +On April 08 2011 10:34 jalstar wrote:
Basically, shit like this is why people hate math. If teachers tried to make math fun instead of throwing retarded trick questions at students then maybe I'd get reactions other than "oh, I hated/failed math" when I tell people I'm majoring in math. To be honest, before these guys learned about matrices, algebra, finite, calc, etc. I'm pretty sure they would answer 288. You can cry ambiguity all you want, but when you were taught about the order of operations and given such a question from a textbook, you would put little thought into it.
Why are you all assuming this is actually thought the same way everywhere ?
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On April 08 2011 10:33 StarStruck wrote:Show nested quote +On April 08 2011 10:27 latan wrote:
I have two degrees in mathematics and i chose 2. because there's no * sign, juxtaposition pretty much means parenthesis in most contexts. afaik there's no universally correct or agreed upon order for these things, so the question is ambiguous, but if something like that were written in a book the answer would be 2 most of the time.
anyway what's the point of the poll? Tell that to practically every grade school textbook. Frigging a.
every textbook in what region? all of them? not really.
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On April 08 2011 10:39 VALERO wrote:Show nested quote +On April 08 2011 10:38 jalstar wrote:On April 08 2011 10:37 VALERO wrote:On April 08 2011 10:34 jalstar wrote:
Basically, shit like this is why people hate math. If teachers tried to make math fun instead of throwing retarded trick questions at students then maybe I'd get reactions other than "oh, I hated/failed math" when I tell people I'm majoring in math. it's not a trick question Yes it is, how is something that fucks with your instincts not a trick question? are still fooled by the penny-in-your-ear magic trick, too?
This thread has sufficiently devolved to the point where its actually starting to redeem itself. Someone call the producers of "Are You Smarter Than a Fifth Grader?"
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On April 08 2011 10:39 Snipinpanda wrote:Show nested quote +On April 08 2011 10:21 mahnini wrote:On April 08 2011 10:18 jalstar wrote:On April 08 2011 10:16 mahnini wrote:On April 08 2011 10:14 Severedevil wrote:On April 08 2011 10:10 mahnini wrote:On April 08 2011 10:02 Zeke50100 wrote:On April 08 2011 09:54 munchmunch wrote:On April 08 2011 09:22 Zeke50100 wrote:On April 08 2011 09:03 munchmunch wrote:
[quote]
LOL, I read that and thought "What a good post, well said!" Then I reread it and realized you were saying the exact opposite of what I thought. I guess a Zeke50100 is an anti-munchmunch.
And to jump into that conversation, "the same" on a semantic level is not the same as being "the same" on a syntactic level. Syntax doesn't mean a thing when it comes to ambiguity because it should be understood that both are simplified to the same level. You're suggesting that "2+1-1" would be more correct than "2-1+1" because it's syntactically more "natural" to somebody's own perception, which is what garbanzo is trying to say. Of course syntax means something when it comes to ambiguity. People who write programming language specifications have to think about syntactic ambiguity all the time. And syntactic ambiguity is by definition the ambiguities that occur before or in the process of simplification. The fact that neither "2+1-1" and "2-1+1" are neither syntactically or semantically ambiguous to most people has nothing to do with it. I agree that one is more natural than the other, but in my mind this is a third concept distinct from ambiguity or correctness (which are themselves very distinct). Anyway, I have to quit the thread now. Nice talking to you... quite fun when I'm procrastinating to meet somebody who can write well but thinks exactly the opposite to myself. Funny you should mention that, since I should probably do some work myself It's easily possible that somebody finds 2+1-1 more ambiguous to 2-1+1, which is something along the lines of what I was trying to say; however, that doesn't make one of them more ambiguous in the grand scheme of things (both being expressions of equal length and all). Anyway, with those of you saying that it would be correct in an informal setting, the problem is that this is on the internet, where an "informal" (which you should really call oral or face-to-face communication via speaking) setting is impossible in the same way sending sarcasm through text without tone is impossible. When typing, we have to assume robotic rule-following, rather than what would "normally" occur when two people communicate. Also, the reason certain languages do not accept parentheses as a function in itself is not a flaw in math, but a flaw in the language itself ^_^ this a million times. this is what i was trying to get at with my you're vs your example (maybe not the best example anyway). in an "informal" situation you understand through context but this situation gives none and therefore you should default to accepted standards. maybe there are some set of rules in upper mathematics that trumps order of operations that i don't know, though no one has brought it up. 48/2(9+3) has no multiplication operator. In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). wiki says there is Right, but people's first instinct is to multiply by the thing immediately to the left, which is 2. If I were writing this problem as part of a formal proof I would put (48/2)(9+3) without a second thought. i agree, but because it is easily misinterpreted doesn't make it necessarily wrong. On April 08 2011 10:19 Snipinpanda wrote:On April 08 2011 10:16 mahnini wrote:On April 08 2011 10:14 Severedevil wrote:On April 08 2011 10:10 mahnini wrote:On April 08 2011 10:02 Zeke50100 wrote:On April 08 2011 09:54 munchmunch wrote:On April 08 2011 09:22 Zeke50100 wrote:On April 08 2011 09:03 munchmunch wrote:
[quote]
LOL, I read that and thought "What a good post, well said!" Then I reread it and realized you were saying the exact opposite of what I thought. I guess a Zeke50100 is an anti-munchmunch.
And to jump into that conversation, "the same" on a semantic level is not the same as being "the same" on a syntactic level. Syntax doesn't mean a thing when it comes to ambiguity because it should be understood that both are simplified to the same level. You're suggesting that "2+1-1" would be more correct than "2-1+1" because it's syntactically more "natural" to somebody's own perception, which is what garbanzo is trying to say. Of course syntax means something when it comes to ambiguity. People who write programming language specifications have to think about syntactic ambiguity all the time. And syntactic ambiguity is by definition the ambiguities that occur before or in the process of simplification. The fact that neither "2+1-1" and "2-1+1" are neither syntactically or semantically ambiguous to most people has nothing to do with it. I agree that one is more natural than the other, but in my mind this is a third concept distinct from ambiguity or correctness (which are themselves very distinct). Anyway, I have to quit the thread now. Nice talking to you... quite fun when I'm procrastinating to meet somebody who can write well but thinks exactly the opposite to myself. Funny you should mention that, since I should probably do some work myself It's easily possible that somebody finds 2+1-1 more ambiguous to 2-1+1, which is something along the lines of what I was trying to say; however, that doesn't make one of them more ambiguous in the grand scheme of things (both being expressions of equal length and all). Anyway, with those of you saying that it would be correct in an informal setting, the problem is that this is on the internet, where an "informal" (which you should really call oral or face-to-face communication via speaking) setting is impossible in the same way sending sarcasm through text without tone is impossible. When typing, we have to assume robotic rule-following, rather than what would "normally" occur when two people communicate. Also, the reason certain languages do not accept parentheses as a function in itself is not a flaw in math, but a flaw in the language itself ^_^ this a million times. this is what i was trying to get at with my you're vs your example (maybe not the best example anyway). in an "informal" situation you understand through context but this situation gives none and therefore you should default to accepted standards. maybe there are some set of rules in upper mathematics that trumps order of operations that i don't know, though no one has brought it up. 48/2(9+3) has no multiplication operator. In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). wiki says there is Is doing something often defining it? what? My point is that you use juxtaposition in place of multiplication "often". You still have yet to define what juxtaposition means in basic algebraic notation. So it depends on the notation that you have to agree upon.
Since when did "often" mean "used, but not actually correct"? Wikipedia has the word "can" in there, as in, "able to". In my world, "able to", in reference to mathematics, means "legal", and I'm pretty sure nearly every mathematician would agree that being able to do something in math means it's legal.
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lol I failed the first one. It is generally invalid CS syntax to multiply using ()
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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.
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Hahaha, it looks like (1/2)x to me because of my constant use of calculators.
Also, I have a deep hatred of using parenthesis when inputing equations on the calculator unless absolutely necessary because of how difficult it makes the equation to read.
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On April 08 2011 10:44 Zeke50100 wrote:Show nested quote +On April 08 2011 10:39 Snipinpanda wrote:On April 08 2011 10:21 mahnini wrote:On April 08 2011 10:18 jalstar wrote:On April 08 2011 10:16 mahnini wrote:On April 08 2011 10:14 Severedevil wrote:On April 08 2011 10:10 mahnini wrote:On April 08 2011 10:02 Zeke50100 wrote:On April 08 2011 09:54 munchmunch wrote:On April 08 2011 09:22 Zeke50100 wrote:
[quote]
Syntax doesn't mean a thing when it comes to ambiguity because it should be understood that both are simplified to the same level. You're suggesting that "2+1-1" would be more correct than "2-1+1" because it's syntactically more "natural" to somebody's own perception, which is what garbanzo is trying to say. Of course syntax means something when it comes to ambiguity. People who write programming language specifications have to think about syntactic ambiguity all the time. And syntactic ambiguity is by definition the ambiguities that occur before or in the process of simplification. The fact that neither "2+1-1" and "2-1+1" are neither syntactically or semantically ambiguous to most people has nothing to do with it. I agree that one is more natural than the other, but in my mind this is a third concept distinct from ambiguity or correctness (which are themselves very distinct). Anyway, I have to quit the thread now. Nice talking to you... quite fun when I'm procrastinating to meet somebody who can write well but thinks exactly the opposite to myself. Funny you should mention that, since I should probably do some work myself It's easily possible that somebody finds 2+1-1 more ambiguous to 2-1+1, which is something along the lines of what I was trying to say; however, that doesn't make one of them more ambiguous in the grand scheme of things (both being expressions of equal length and all). Anyway, with those of you saying that it would be correct in an informal setting, the problem is that this is on the internet, where an "informal" (which you should really call oral or face-to-face communication via speaking) setting is impossible in the same way sending sarcasm through text without tone is impossible. When typing, we have to assume robotic rule-following, rather than what would "normally" occur when two people communicate. Also, the reason certain languages do not accept parentheses as a function in itself is not a flaw in math, but a flaw in the language itself ^_^ this a million times. this is what i was trying to get at with my you're vs your example (maybe not the best example anyway). in an "informal" situation you understand through context but this situation gives none and therefore you should default to accepted standards. maybe there are some set of rules in upper mathematics that trumps order of operations that i don't know, though no one has brought it up. 48/2(9+3) has no multiplication operator. In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). wiki says there is Right, but people's first instinct is to multiply by the thing immediately to the left, which is 2. If I were writing this problem as part of a formal proof I would put (48/2)(9+3) without a second thought. i agree, but because it is easily misinterpreted doesn't make it necessarily wrong. On April 08 2011 10:19 Snipinpanda wrote:On April 08 2011 10:16 mahnini wrote:On April 08 2011 10:14 Severedevil wrote:On April 08 2011 10:10 mahnini wrote:On April 08 2011 10:02 Zeke50100 wrote:On April 08 2011 09:54 munchmunch wrote:On April 08 2011 09:22 Zeke50100 wrote:
[quote]
Syntax doesn't mean a thing when it comes to ambiguity because it should be understood that both are simplified to the same level. You're suggesting that "2+1-1" would be more correct than "2-1+1" because it's syntactically more "natural" to somebody's own perception, which is what garbanzo is trying to say. Of course syntax means something when it comes to ambiguity. People who write programming language specifications have to think about syntactic ambiguity all the time. And syntactic ambiguity is by definition the ambiguities that occur before or in the process of simplification. The fact that neither "2+1-1" and "2-1+1" are neither syntactically or semantically ambiguous to most people has nothing to do with it. I agree that one is more natural than the other, but in my mind this is a third concept distinct from ambiguity or correctness (which are themselves very distinct). Anyway, I have to quit the thread now. Nice talking to you... quite fun when I'm procrastinating to meet somebody who can write well but thinks exactly the opposite to myself. Funny you should mention that, since I should probably do some work myself It's easily possible that somebody finds 2+1-1 more ambiguous to 2-1+1, which is something along the lines of what I was trying to say; however, that doesn't make one of them more ambiguous in the grand scheme of things (both being expressions of equal length and all). Anyway, with those of you saying that it would be correct in an informal setting, the problem is that this is on the internet, where an "informal" (which you should really call oral or face-to-face communication via speaking) setting is impossible in the same way sending sarcasm through text without tone is impossible. When typing, we have to assume robotic rule-following, rather than what would "normally" occur when two people communicate. Also, the reason certain languages do not accept parentheses as a function in itself is not a flaw in math, but a flaw in the language itself ^_^ this a million times. this is what i was trying to get at with my you're vs your example (maybe not the best example anyway). in an "informal" situation you understand through context but this situation gives none and therefore you should default to accepted standards. maybe there are some set of rules in upper mathematics that trumps order of operations that i don't know, though no one has brought it up. 48/2(9+3) has no multiplication operator. In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). wiki says there is Is doing something often defining it? what? My point is that you use juxtaposition in place of multiplication "often". You still have yet to define what juxtaposition means in basic algebraic notation. So it depends on the notation that you have to agree upon. Since when did "often" mean "used, but not actually correct"? Wikipedia has the word "can" in there, as in, "able to". In my world, "able to", in reference to mathematics, means "legal", and I'm pretty sure nearly every mathematician would agree that being able to do something in math means it's legal.
By often, I mean, some notation definitions. This doesn't not mean all notation definitions. The fact that there is this much confusion in the thread shows this.
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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).
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On April 08 2011 10:44 Zeke50100 wrote:Show nested quote +On April 08 2011 10:39 Snipinpanda wrote:On April 08 2011 10:21 mahnini wrote:On April 08 2011 10:18 jalstar wrote:On April 08 2011 10:16 mahnini wrote:On April 08 2011 10:14 Severedevil wrote:On April 08 2011 10:10 mahnini wrote:On April 08 2011 10:02 Zeke50100 wrote:On April 08 2011 09:54 munchmunch wrote:On April 08 2011 09:22 Zeke50100 wrote:
[quote]
Syntax doesn't mean a thing when it comes to ambiguity because it should be understood that both are simplified to the same level. You're suggesting that "2+1-1" would be more correct than "2-1+1" because it's syntactically more "natural" to somebody's own perception, which is what garbanzo is trying to say. Of course syntax means something when it comes to ambiguity. People who write programming language specifications have to think about syntactic ambiguity all the time. And syntactic ambiguity is by definition the ambiguities that occur before or in the process of simplification. The fact that neither "2+1-1" and "2-1+1" are neither syntactically or semantically ambiguous to most people has nothing to do with it. I agree that one is more natural than the other, but in my mind this is a third concept distinct from ambiguity or correctness (which are themselves very distinct). Anyway, I have to quit the thread now. Nice talking to you... quite fun when I'm procrastinating to meet somebody who can write well but thinks exactly the opposite to myself. Funny you should mention that, since I should probably do some work myself It's easily possible that somebody finds 2+1-1 more ambiguous to 2-1+1, which is something along the lines of what I was trying to say; however, that doesn't make one of them more ambiguous in the grand scheme of things (both being expressions of equal length and all). Anyway, with those of you saying that it would be correct in an informal setting, the problem is that this is on the internet, where an "informal" (which you should really call oral or face-to-face communication via speaking) setting is impossible in the same way sending sarcasm through text without tone is impossible. When typing, we have to assume robotic rule-following, rather than what would "normally" occur when two people communicate. Also, the reason certain languages do not accept parentheses as a function in itself is not a flaw in math, but a flaw in the language itself ^_^ this a million times. this is what i was trying to get at with my you're vs your example (maybe not the best example anyway). in an "informal" situation you understand through context but this situation gives none and therefore you should default to accepted standards. maybe there are some set of rules in upper mathematics that trumps order of operations that i don't know, though no one has brought it up. 48/2(9+3) has no multiplication operator. In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). wiki says there is Right, but people's first instinct is to multiply by the thing immediately to the left, which is 2. If I were writing this problem as part of a formal proof I would put (48/2)(9+3) without a second thought. i agree, but because it is easily misinterpreted doesn't make it necessarily wrong. On April 08 2011 10:19 Snipinpanda wrote:On April 08 2011 10:16 mahnini wrote:On April 08 2011 10:14 Severedevil wrote:On April 08 2011 10:10 mahnini wrote:On April 08 2011 10:02 Zeke50100 wrote:On April 08 2011 09:54 munchmunch wrote:On April 08 2011 09:22 Zeke50100 wrote:
[quote]
Syntax doesn't mean a thing when it comes to ambiguity because it should be understood that both are simplified to the same level. You're suggesting that "2+1-1" would be more correct than "2-1+1" because it's syntactically more "natural" to somebody's own perception, which is what garbanzo is trying to say. Of course syntax means something when it comes to ambiguity. People who write programming language specifications have to think about syntactic ambiguity all the time. And syntactic ambiguity is by definition the ambiguities that occur before or in the process of simplification. The fact that neither "2+1-1" and "2-1+1" are neither syntactically or semantically ambiguous to most people has nothing to do with it. I agree that one is more natural than the other, but in my mind this is a third concept distinct from ambiguity or correctness (which are themselves very distinct). Anyway, I have to quit the thread now. Nice talking to you... quite fun when I'm procrastinating to meet somebody who can write well but thinks exactly the opposite to myself. Funny you should mention that, since I should probably do some work myself It's easily possible that somebody finds 2+1-1 more ambiguous to 2-1+1, which is something along the lines of what I was trying to say; however, that doesn't make one of them more ambiguous in the grand scheme of things (both being expressions of equal length and all). Anyway, with those of you saying that it would be correct in an informal setting, the problem is that this is on the internet, where an "informal" (which you should really call oral or face-to-face communication via speaking) setting is impossible in the same way sending sarcasm through text without tone is impossible. When typing, we have to assume robotic rule-following, rather than what would "normally" occur when two people communicate. Also, the reason certain languages do not accept parentheses as a function in itself is not a flaw in math, but a flaw in the language itself ^_^ this a million times. this is what i was trying to get at with my you're vs your example (maybe not the best example anyway). in an "informal" situation you understand through context but this situation gives none and therefore you should default to accepted standards. maybe there are some set of rules in upper mathematics that trumps order of operations that i don't know, though no one has brought it up. 48/2(9+3) has no multiplication operator. In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). wiki says there is Is doing something often defining it? what? My point is that you use juxtaposition in place of multiplication "often". You still have yet to define what juxtaposition means in basic algebraic notation. So it depends on the notation that you have to agree upon. Since when did "often" mean "used, but not actually correct"? Wikipedia has the word "can" in there, as in, "able to". In my world, "able to", in reference to mathematics, means "legal", and I'm pretty sure nearly every mathematician would agree that being able to do something in math means it's legal.
So...
1/xy = y/x
True or false?
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On April 08 2011 10:40 jalstar wrote:Show nested quote +On April 08 2011 10:39 VALERO wrote:On April 08 2011 10:38 jalstar wrote:On April 08 2011 10:37 VALERO wrote:On April 08 2011 10:34 jalstar wrote:
Basically, shit like this is why people hate math. If teachers tried to make math fun instead of throwing retarded trick questions at students then maybe I'd get reactions other than "oh, I hated/failed math" when I tell people I'm majoring in math. it's not a trick question Yes it is, how is something that fucks with your instincts not a trick question? are still fooled by the penny-in-your-ear magic trick, too? I wasn't fooled by this, so your question makes no sense. Just because I'm not fooled by it doesn't mean it's not a trick. You're a troll anyway.
it's not a trick question if there's an obvious correct way to do it
'obvious' is pretty ambiguous because retards can find pretty clever ways of getting things wrong
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I got 288, which was my first thought, but the sheer amount of 2's made me question myself.
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I never use PEMDAS and got it right. I don't understand how people insert the additional bracket? But I guess that's why I didn't struggle with it. This isn't a test of your math knowledge or intelligence really. It's how well you understand how to properly evaluate a certain math problem more than anything.
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On April 08 2011 10:25 Severedevil wrote:Show nested quote +On April 08 2011 10:21 jinorazi wrote:On April 08 2011 10:18 bkrow wrote:
It isn't a matter of "should" or "shouldn't" be written in a particular way.. If you calculate the presented question in the way that it is written in the OP you get 288? I haven't read 36 pages of comments but simply focussing on the question itself.. how is there an issue? to quote: In algebra, multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two). some read it 42/(2(3+9)) while others read it (42/2)(3+9) Are you seriously suggesting that you'd read 2/xy as equivalent to 2y/x. Really?
i wasnt suggesting anything. i was just informing him on the situation because he hasnt read up on the long discussion. the quote was to explain the confusion this is causing and it was quoted from a post somewhere in the thread. hence why people see it as 42/(2(3+9)).
its obvious this expression is not clear like (3+9)(42/2), otherwise we wouldnt be having this long of a thread.
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On April 08 2011 10:49 Zeke50100 wrote:Show nested quote +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).
If I had this question on the test, I would ask for clarification because it's not unambiguous.
No test questions are ever structured like this for a reason.
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ok i voted 2, then 2s later i realize my mistake 
funny that people who dont know math would get it right LOL
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EPT
