EPTA Simple Math Problem? - Page 88
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Ropid
Germany3557 Posts
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Nineteen_
United States34 Posts
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nam nam
Sweden4672 Posts
On April 09 2011 08:44 Nineteen_ wrote: oh my god the answer to fisrt one is 2 so many people did it wrong and are studing science math ,,, omg kinda funny Yes, the last 87 pages have been full of laughs. | ||
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ondik
Czech Republic2908 Posts
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NarutO
Germany18839 Posts
On April 09 2011 08:47 nam nam wrote: Yes, the last 87 pages have been full of laughs. 48/2(9+3) is the same as 48÷2(9+3) According to wikipedia, according to wolfram alpha and according to lots of math majors. Wikipedia states that ÷ is just different way of writing / .. On April 09 2011 08:47 ondik wrote: all my life i've been under impression that ÷ = / but it seems it doesn't according to poll? / does equal ÷ | ||
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aztrorisk
United States896 Posts
I put 2 and 1/(2x) as the answers. Am I right or wrong? | ||
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Cloud9157
United States2968 Posts
On April 09 2011 08:47 ondik wrote: all my life i've been under impression that ÷ = / but it seems it doesn't according to poll? People (including myself) are simply using order of operations incorrectly. We read it as 48/ (2(3+9)) instead of 48/2 x (3+9). | ||
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Slithe
United States985 Posts
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quiggy
Canada58 Posts
On April 09 2011 08:54 Cloud9157 wrote: People (including myself) are simply using order of operations incorrectly. We read it as 48/ (2(3+9)) instead of 48/2 x (3+9). People like you are creating extra brackets to complete the equation. it is not 48/(2(9+3)) it is 48/2(9+3) | ||
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ondik
Czech Republic2908 Posts
On April 09 2011 08:54 Cloud9157 wrote: People (including myself) are simply using order of operations incorrectly. We read it as 48/ (2(3+9)) instead of 48/2 x (3+9). ok..then why if 288 is right isn't 1/(2*x) wrong? | ||
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emperorchampion
Canada9496 Posts
On April 09 2011 08:52 aztrorisk wrote: Reading the first few comments, I was sure that I was wrong because I believe that you need to distribute first because the parenthesis tells us that it is attached. But with the last few comments, I am unsure if I am right or wrong. I put 2 and 1/(2x) as the answers. Am I right or wrong? Hate to be obscure, but essentially the premise is that there is no "right or wrong" answer here. Clearly, it is a matter of convention- and not a matter of the actual math it self. From the two pieces I've read from this thread, both suggest that the convention in "Math education" has become the problem, and not the math it self! I would say that about 90% of the thread suggests that this is true -_- http://math.berkeley.edu/~wu/order5.pdf http://www.maa.org/devlin/LockhartsLament.pdf Both of those are highly recommended reads.  Sorry for not answering your question! | ||
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NarutO
Germany18839 Posts
On April 09 2011 08:54 Cloud9157 wrote: People (including myself) are simply using order of operations incorrectly. We read it as 48/ (2(3+9)) instead of 48/2 x (3+9). Its actually just about writing the formula. If you would use it would be 2 clearly, but the way it is written right now, its 288 because there's no specification in what order to read - so its read from left to right. Division and multiplication have the same priority. so its 48/2 * 12. | ||
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Maxwell3
United States88 Posts
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RedBarchetta
49 Posts
On April 09 2011 08:52 aztrorisk wrote: Reading the first few comments, I was sure that I was wrong because I believe that you need to distribute first because the parenthesis tells us that it is attached. But with the last few comments, I am unsure if I am right or wrong. I put 2 and 1/(2x) as the answers. Am I right or wrong? Yes you are unfortunately. In the mathematical order of operations * has the same priority as /. When things have the same priority they are done left to right. Thus 1/2x=(1/2)*x since the operation on the left is done first. 1/2x would have the multiplication occuring first, which is incorrect. The same principle applies to the OP. The answer is 2888 because the division is done first and then dividend is multiplied by (9+3) or 12. Running through the problem: 48÷2(9+3) 48/2=24 24*(9+3)=24*12 24*12=288 | ||
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Munk-E
United States672 Posts
Explanation! 48÷2(9+3)= First we distribute 48÷(2*18)+(2*3) solve so far 48/36+6 order of operations says we divide first. (4/3)+6 and solve! 22/3! | ||
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quiggy
Canada58 Posts
If you use 1+1-1+1-1+1...=0 as an example, it also means: (1+1)-(1+1)-(1+1)..=1 There is no right or wrong answer. The limitations of the equation cause this | ||
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Reborn58
United States238 Posts
The answer is 288. | ||
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tpir
United States53 Posts
Pic of TI-85 vs. TI-86: http://img339.imageshack.us/img339/9549/headasplode.jpg Screen grab of pertinent order of operations section: http://i.imgur.com/aP7Gg.jpg Source: http://math.ucsd.edu/~ashenk/Calculators/Getting_Started_TI-86.pdf | ||
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aztrorisk
United States896 Posts
On April 09 2011 08:57 emperorchampion wrote: Hate to be obscure, but essentially the premise is that there is no "right or wrong" answer here. Clearly, it is a matter of convention- and not a matter of the actual math it self. From the two pieces I've read from this thread, both suggest that the convention in "Math education" has become the problem, and not the math it self! I would say that about 90% of the thread suggests that this is true -_- http://math.berkeley.edu/~wu/order5.pdf http://www.maa.org/devlin/LockhartsLament.pdf Both of those are highly recommended reads. Sorry for not answering your question! To think, I used to like math. T.T I'm gonna be so confused for the SAT now. But thanks for the articles. Interesting reads. | ||
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tpir
United States53 Posts
http://img19.imageshack.us/img19/6273/ducy.jpg | ||
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