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On April 08 2011 12:06 space_yes wrote:Show nested quote +On April 08 2011 12:05 DarkPlasmaBall wrote:On April 08 2011 05:35 Retgery wrote:
Oh dear...who picked 288?
The point of Bedmas is to get rid of brackets first. Oh dear: 1. The answer is 288 >.> 2. Bedmas? Brackets? Those aren't brackets lol ( ) are parentheses [ ] are brackets { } are braces It's called PEMDAS  Parentheses, Exponents, Multiplication/ Division, Addition/ Subtraction (Please Excuse My Dear Aunt Sally) I'm getting a masters degree in math education in a month... I can't wait to start teaching kids! Don't tell me you picked 1/(2x)?
Haha actually I didn't vote in that poll, because I know that my kids (from student teaching and tutoring for several years) mess up on that all the time from the context. I have them either use vertical fractions (with the x clearly outside of the fraction or in the appropriate numerator or denominator part) or I just have them change the fraction to a decimal (so .5), so it's a non-issue and it's never ambiguous.
Possibly a cop-out for this poll, but as far as teaching is concerned, it's incredibly helpful
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48...........48
---------- = -------- = 2
2(9+3).......24
Also PEMDAS....
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I was always taught to do multiplication and division from left to right but my friend was taught to do multiplication before division :/
I voted 288, google agrees with me btw =)
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The correct answer is that real mathematicians don't use the division sign because it's misleading. The actual, official rules behind it are obscure to the extent where someone taking a Math degree doesn't know what they are. For that matter, neither is /. When mathematicians talk online, though, / typically means "big line" unless it's got brackets on it.
So correct or not, the "msn" variety of math syntax recognizes 1/2x as (1/(2x)), at least where I'm from. This is because we always carry through fractions and never write something like (1/2)*x. It would always be x/2 or even 1x/2 if 1 was another number.
For the first one, you do the brackets first, yes, but then you're left with a similar situation. If I used the / sign while asking my prof a question on a message board, then 48/2(9+3) is 2.
Furthermore, the rule of PEMDAS is that multiplication comes before division. Hence, we perform our task as follows:
48÷2(9+3) = 48÷2(12) = 48÷2*12 = 48÷24 = 2
The reason this must be specified is that 48÷2*12 can either be read left to right (a mistake) or by using multiplication first (the correct response).
So yeah, I'm a mathematician and I think it's 2.
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On April 08 2011 12:15 Count9 wrote:
I was always taught to do multiplication and division from left to right but my friend was taught to do multiplication before division :/
I voted 288, google agrees with me btw =)
And this is why we cant trust calculators.
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On April 08 2011 12:12 DarkPlasmaBall wrote:Show nested quote +On April 08 2011 12:06 space_yes wrote:On April 08 2011 12:05 DarkPlasmaBall wrote:On April 08 2011 05:35 Retgery wrote:
Oh dear...who picked 288?
The point of Bedmas is to get rid of brackets first. Oh dear: 1. The answer is 288 >.> 2. Bedmas? Brackets? Those aren't brackets lol ( ) are parentheses [ ] are brackets { } are braces It's called PEMDAS Parentheses, Exponents, Multiplication/ Division, Addition/ Subtraction (Please Excuse My Dear Aunt Sally) I'm getting a masters degree in math education in a month... I can't wait to start teaching kids! Don't tell me you picked 1/(2x)? Haha actually I didn't vote in that poll, because I know that my kids (from student teaching and tutoring for several years) mess up on that all the time from the context. I have them either use vertical fractions (with the x clearly outside of the fraction or in the appropriate numerator or denominator part) or I just have them change the fraction to a decimal (so .5), so it's a non-issue and it's never ambiguous. Possibly a cop-out for this poll, but as far as teaching is concerned, it's incredibly helpful
Yeah it's only tricky b/c the fraction is all on one line. But then if the OP used an image to show the fraction vertically the poll wouldn't be very fun ^^
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On April 08 2011 12:15 SharkSpider wrote:
The correct answer is that real mathematicians don't use the division sign because it's misleading. The actual, official rules behind it are obscure to the extent where someone taking a Math degree doesn't know what they are. For that matter, neither is /. When mathematicians talk online, though, / typically means "big line" unless it's got brackets on it.
So correct or not, the "msn" variety of math syntax recognizes 1/2x as (1/(2x)), at least where I'm from. This is because we always carry through fractions and never write something like (1/2)*x. It would always be x/2 or even 1x/2 if 1 was another number.
For the first one, you do the brackets first, yes, but then you're left with a similar situation. If I used the / sign while asking my prof a question on a message board, then 48/2(9+3) is 2.
Furthermore, the rule of PEMDAS is that multiplication comes before division. Hence, we perform our task as follows:
48÷2(9+3) = 48÷2(12) = 48÷2*12 = 48÷24 = 2
The reason this must be specified is that 48÷2*12 can either be read left to right (a mistake) or by using multiplication first (the correct response).
So yeah, I'm a mathematician and I think it's 2.
I was taught the MD in PEMDAS was Multiplication and Division from left to right, just like AS is Addition and Subtraction from left to right. No one would do 1-1+2=-2.
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I really dislike the comments here "Oh, my calculator says so." "Oh, google says so"
This is math. You should be able to work it out, step by step, and understand where the differences in opinions (lulz...) lie.
Read the formula out loud. Write it out the way you interpret it as. Write it out the way other people have described it as. It's not that hard.
On April 08 2011 12:16 space_yes wrote:Show nested quote +On April 08 2011 12:12 DarkPlasmaBall wrote:On April 08 2011 12:06 space_yes wrote:On April 08 2011 12:05 DarkPlasmaBall wrote:On April 08 2011 05:35 Retgery wrote:
Oh dear...who picked 288?
The point of Bedmas is to get rid of brackets first. Oh dear: 1. The answer is 288 >.> 2. Bedmas? Brackets? Those aren't brackets lol ( ) are parentheses [ ] are brackets { } are braces It's called PEMDAS Parentheses, Exponents, Multiplication/ Division, Addition/ Subtraction (Please Excuse My Dear Aunt Sally) I'm getting a masters degree in math education in a month... I can't wait to start teaching kids! Don't tell me you picked 1/(2x)? Haha actually I didn't vote in that poll, because I know that my kids (from student teaching and tutoring for several years) mess up on that all the time from the context. I have them either use vertical fractions (with the x clearly outside of the fraction or in the appropriate numerator or denominator part) or I just have them change the fraction to a decimal (so .5), so it's a non-issue and it's never ambiguous. Possibly a cop-out for this poll, but as far as teaching is concerned, it's incredibly helpful Yeah it's only tricky b/c the fraction is all on one line. But then if the OP used an image to show the fraction vertically the poll wouldn't be very fun ^^
The OP used the division symbol. Your interpretation of the division symbol is what threw you off. Don't blame the division symbol.
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On April 08 2011 05:35 cursor wrote:
pedmas
i thought it was pemdas, lol
i voted 2
eh ur prolly just trolling anyways
holy shit this has 48 pages
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Kentor
United States5784 Posts
On April 08 2011 11:57 -{Cake}- wrote:
math.berkeley.edu/~wu/order5.pdf
^interesting
just sayin
nice. thanks for sharing. standardized tests are terrible lol
wow he has a lot of other stuff http://math.berkeley.edu/~wu/
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On April 08 2011 12:15 SharkSpider wrote:
Furthermore, the rule of PEMDAS is that multiplication comes before division. Hence, we perform our task as follows:
48÷2(9+3) = 48÷2(12) = 48÷2*12 = 48÷24 = 2
The reason this must be specified is that 48÷2*12 can either be read left to right (a mistake) or by using multiplication first (the correct response).
So yeah, I'm a mathematician and I think it's 2.
You cannot be a mathematician and make a mistake as blatantly obvious as stating that PEMDAS claims that multiplication comes before division.
They're done simultaneously, from left to right, which is exactly why you do 48÷2 before multiplying that value (24) by 12 (the sum from the parentheses).
I have a degree in math too, but you don't need one to remember that the MD go together and the AS go together. That was taught in elementary school.
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Off topic question for mathematicians who have taken some algebra or topology, how important has rigorously memorizing definitions been for you in understanding what you're working with?
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On April 08 2011 12:19 DarkPlasmaBall wrote:Show nested quote +On April 08 2011 12:15 SharkSpider wrote:
Furthermore, the rule of PEMDAS is that multiplication comes before division. Hence, we perform our task as follows:
48÷2(9+3) = 48÷2(12) = 48÷2*12 = 48÷24 = 2
The reason this must be specified is that 48÷2*12 can either be read left to right (a mistake) or by using multiplication first (the correct response).
So yeah, I'm a mathematician and I think it's 2. You cannot be a mathematician and make a mistake as blatantly obvious as stating that PEMDAS claims that multiplication comes before division. They're done simultaneously, from left to right, which is exactly why you do 48÷2 before multiplying that value (24) by 12 (the sum from the parentheses). I have a degree in math too, but you don't need one to remember that the MD go together and the AS go together. That was taught in elementary school.
Just a minor niggle. Not "simultaneously". They are considered of the same tier/level/insertsynonymhere.
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The original problem is a kind of "hahaha i got you! trololol" idiotic game that is designed to trap unsuspecting people by phrasing with unreasonably convoluted rules. This is why most people don't learn in school because we don't see the point when there will never be a situation where someone hands you such a problem that is written so poorly considering the division sign isn't used after fractions are introduced.
I guess it makes some unsocial people feel better about how they have wasted their time and make them think that they waste it better than other people who would rather waste time say, playing starcraft, or going for a walk etc.
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I got it right! 288.
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On April 08 2011 12:18 Kentor wrote:Show nested quote +On April 08 2011 11:57 -{Cake}- wrote:
math.berkeley.edu/~wu/order5.pdf
^interesting
just sayin nice. thanks for sharing. standardized tests are terrible lol wow he has a lot of other stuff http://math.berkeley.edu/~wu/
oh wow, didn't notice that, google took me right to the pdf lol
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Got it right....Although taking calculus and linear algebra in university probably has something to do with it....
Also silly americans, BEDMAS is soooo much easier than PEMDAS to remember.
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On April 08 2011 12:16 space_yes wrote:Show nested quote +On April 08 2011 12:12 DarkPlasmaBall wrote:On April 08 2011 12:06 space_yes wrote:On April 08 2011 12:05 DarkPlasmaBall wrote:On April 08 2011 05:35 Retgery wrote:
Oh dear...who picked 288?
The point of Bedmas is to get rid of brackets first. Oh dear: 1. The answer is 288 >.> 2. Bedmas? Brackets? Those aren't brackets lol ( ) are parentheses [ ] are brackets { } are braces It's called PEMDAS Parentheses, Exponents, Multiplication/ Division, Addition/ Subtraction (Please Excuse My Dear Aunt Sally) I'm getting a masters degree in math education in a month... I can't wait to start teaching kids! Don't tell me you picked 1/(2x)? Haha actually I didn't vote in that poll, because I know that my kids (from student teaching and tutoring for several years) mess up on that all the time from the context. I have them either use vertical fractions (with the x clearly outside of the fraction or in the appropriate numerator or denominator part) or I just have them change the fraction to a decimal (so .5), so it's a non-issue and it's never ambiguous. Possibly a cop-out for this poll, but as far as teaching is concerned, it's incredibly helpful Yeah it's only tricky b/c the fraction is all on one line. But then if the OP used an image to show the fraction vertically the poll wouldn't be very fun ^^
I completely agree ^^
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On April 08 2011 12:20 JinDesu wrote:Show nested quote +On April 08 2011 12:19 DarkPlasmaBall wrote:On April 08 2011 12:15 SharkSpider wrote:
Furthermore, the rule of PEMDAS is that multiplication comes before division. Hence, we perform our task as follows:
48÷2(9+3) = 48÷2(12) = 48÷2*12 = 48÷24 = 2
The reason this must be specified is that 48÷2*12 can either be read left to right (a mistake) or by using multiplication first (the correct response).
So yeah, I'm a mathematician and I think it's 2. You cannot be a mathematician and make a mistake as blatantly obvious as stating that PEMDAS claims that multiplication comes before division. They're done simultaneously, from left to right, which is exactly why you do 48÷2 before multiplying that value (24) by 12 (the sum from the parentheses). I have a degree in math too, but you don't need one to remember that the MD go together and the AS go together. That was taught in elementary school. Just a minor niggle. Not "simultaneously". They are considered of the same tier/level/insertsynonymhere.
Good call. Thanks for the clarification Same tier/ level is a much better way of putting it.
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EPT
