Author Topic: the math apocalypse: 48�2(9+3) = ? (Read 16199 times)

ZER� · September 23, 2014, 05:44:52 PM

Quote from: McJobless on September 23, 2014, 05:23:04 PM

I made a program to demonstrate:

[im width=800]http://i.imgur.com/94OpHGw.png[/img]

I disagree with the Berkeley Professor's explanation. Somebody might get confused, but following the basic rules we've set out for maths questions I believe it becomes quite obviously 288. Left-to-Right and PEDMAS (with Division/Multiplication and Addiction/Subtraction as the same priorities) or whatever you call it. You can't just ignore one for the other, they both need to work together.

This is why thousands of people have said PEMDAS is wrong and should not be taught, yet people refuse to do so.

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$trinick · September 23, 2014, 05:49:32 PM

Quote from: ZER� on September 23, 2014, 05:44:52 PM

This is why thousands of people have said PEMDAS is wrong and should not be taught, yet people refuse to do so.

Right. You made me remember this video which I saw a looong time ago and holy stuff is it perfect.

http://www.youtube.com/watch?v=y9h1oqv21Vs

Oasis · September 23, 2014, 06:02:43 PM

Quote from: $trinick on September 23, 2014, 05:49:32 PM

Right. You made me remember this video which I saw a looong time ago and holy stuff is it perfect.

http://www.youtube.com/watch?v=y9h1oqv21Vs

God I love MinutePhysics.

Jubel · September 23, 2014, 06:32:49 PM

https://www.youtube.com/watch?v=a-e8fzqv3CE

Edit: I know understand what $trinick is trying to say.
48�2(9+3) is ambiguous.

However, if the question were formatted correctly as

then the answer would be undeniably 288.

Doomonkey · September 23, 2014, 06:33:13 PM

http://doe.sd.gov/contentstandards/documents/6_alg.pdf

Look, the state of South Dakota says you should multiply and divide from left to right. I'm sure there are plenty of math doctorates whose input goes into this curriculum.

It looks like Virginia does too. All you have to do is search for "order of operations site:.gov"

Also, the NSA https://www.nsa.gov/academia/_files/collected_learning/elementary/patterns/order_operation.pdf. They use an example 18 ÷ 3 x 2

dkamm65 · September 23, 2014, 06:46:24 PM

Quote from: $trinick on September 23, 2014, 05:49:32 PM

Right. You made me remember this video which I saw a looong time ago and holy stuff is it perfect.

http://www.youtube.com/watch?v=y9h1oqv21Vs

He even loving says in the video "While the order of operations isn't technically wrong, it's morally wrong." From a getting the correct answer standpoint, there is absolutely no problem with it.

And for the record, I was never taught ever that multiplication comes before division, or that addition comes before subtraction. It was always left to right. That will still give you the correct answer every time, even if it's "morally" wrong.

Like I've said, this problem is only ambiguous for people who do not understand the order of operations.

$trinick · September 23, 2014, 07:10:11 PM

He explains that it's not technically wrong because it gets an answer which is usually the correct answer. But that's not even what I'm talking about, I'm talking about how the question is ambiguous which is something he very clearly goes over.

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48�2(9+3) = ?

Author Topic: the math apocalypse: 48�2(9+3) = ? (Read 16199 times)

ZER�

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$trinick

Oasis

Jubel

Doomonkey

dkamm65

$trinick