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Australia8532 Posts
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?
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On April 08 2011 10:16 mahnini wrote:Show nested quote +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:On April 08 2011 08:59 Zeke50100 wrote:On April 08 2011 08:52 garbanzo wrote:On April 08 2011 08:50 Mailing wrote: [quote]
If you can find some evidence of this.. Yes, I would like some source that it can definitively only be read one way. And you didn't really answer my question. If you were to ask someone a question, and you wanted absolutely no confusion, then would you consider choosing one notation over the other? I think you're lying to yourself if you say otherwise. I don't get how "these two things are exactly the same" do not equate to "these two things are interchangeable, and therefore one is no more ambiguous than the other" in your mind. 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. Show nested 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). 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.
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?
The problem is poorly written and calculating it correctly requires second-guessing your intuition, something that proper parentheses use would remove.
1/2x is also overly ambiguous, to the point where the majority in the thread are actually getting it wrong. I always write 1/(2x) or (1/2)x because I don't trust computer parsers to always get that one right. (and it turns out Wolfram Alpha fails at it)
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On April 08 2011 10:16 mahnini wrote:Show nested quote +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:On April 08 2011 08:59 Zeke50100 wrote:On April 08 2011 08:52 garbanzo wrote:On April 08 2011 08:50 Mailing wrote: [quote]
If you can find some evidence of this.. Yes, I would like some source that it can definitively only be read one way. And you didn't really answer my question. If you were to ask someone a question, and you wanted absolutely no confusion, then would you consider choosing one notation over the other? I think you're lying to yourself if you say otherwise. I don't get how "these two things are exactly the same" do not equate to "these two things are interchangeable, and therefore one is no more ambiguous than the other" in your mind. 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. Show nested 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). wiki says there is
Is doing something often defining it?
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My TI-84 says parentheses can be used as assumed multiplication. So does my TI-83. And so does my friend's TI-89. And so do every math teacher and professor I have ever met.
@Snipinpanda: You're not reading it right. It says variables are often juxtaposed (because it is lega), and then continues to say, on a different train of thought, that the same can be done with numbers involving parentheses.
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On April 08 2011 10:18 jalstar wrote:Show nested quote +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:On April 08 2011 08:59 Zeke50100 wrote:On April 08 2011 08:52 garbanzo wrote: [quote] Yes, I would like some source that it can definitively only be read one way. And you didn't really answer my question. If you were to ask someone a question, and you wanted absolutely no confusion, then would you consider choosing one notation over the other?
I think you're lying to yourself if you say otherwise.
I don't get how "these two things are exactly the same" do not equate to "these two things are interchangeable, and therefore one is no more ambiguous than the other" in your mind. 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:Show nested quote +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:On April 08 2011 08:59 Zeke50100 wrote:On April 08 2011 08:52 garbanzo wrote: [quote] Yes, I would like some source that it can definitively only be read one way. And you didn't really answer my question. If you were to ask someone a question, and you wanted absolutely no confusion, then would you consider choosing one notation over the other?
I think you're lying to yourself if you say otherwise.
I don't get how "these two things are exactly the same" do not equate to "these two things are interchangeable, and therefore one is no more ambiguous than the other" in your mind. 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?
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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)
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This thread seriously needs to be stopped. The arguments are just going in cycles.
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i put 2. i asked my gf (engineering math) and her two friends (both engineers) and they told me that it was 288 because at a certain point in pemdas, you just go left to right. i wanted to multiply before i divided. it's no big deal for me because i'm not a math oriented person
what we really need is day9's input on the matter.
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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? Because OP does not specify the notation. There are multiple notations how to write arithmetic expressions.
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On April 08 2011 10:21 jinorazi wrote:Show nested quote +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?
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On April 08 2011 10:21 mahnini wrote:Show nested quote +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:On April 08 2011 08:59 Zeke50100 wrote: [quote]
I don't get how "these two things are exactly the same" do not equate to "these two things are interchangeable, and therefore one is no more ambiguous than the other" in your mind. 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.
They aren't wrong, they're just ugly. I treat math like an art and part of its beauty is its simplicity. Ugly statements like 48/2(9+3) and 1/2x destroy that.
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To lend a hand, 2(9+3) is to be taken as a single expression. (48/2)*(9+3) or 48/(2*(9+3)) would yield 288.
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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
User was warned for this post
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On April 08 2011 10:21 Slithe wrote: This thread seriously needs to be stopped. The arguments are just going in cycles.
Not curious to see at what point it runs out of steam? I'm thinking 100+ pages
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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.
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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
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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?
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On April 08 2011 10:26 MajorityofOne wrote:Show nested quote +On April 08 2011 10:21 Slithe wrote: This thread seriously needs to be stopped. The arguments are just going in cycles. Not curious to see at what point it runs out of steam? I'm thinking 100+ pages You place too much stock on stupidity of TL. I say <50.
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On April 08 2011 10:26 MajorityofOne wrote:Show nested quote +On April 08 2011 10:21 Slithe wrote: This thread seriously needs to be stopped. The arguments are just going in cycles. Not curious to see at what point it runs out of steam? I'm thinking 100+ pages
Just a tad curious, perhaps we should have a pool going to guess the page count.
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On April 08 2011 10:25 WoShiMusashi wrote: To lend a hand, 2(9+3) is to be taken as a single expression. (48/2)*(9+3) or 48/(2*(9+3)) would yield 288.
2(9+3) consists of two separate terms.
BTW, the second expression you listed results in 2
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