Why people can't math...

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Re: Why people can't math...

Postby Nikki Nyx » Tue Jul 18, 2017 2:42 am

When you play fast and loose with math, it affects people's lives.

Internet Theory...
There are allegedly around 6.5 million Finns, right? That's out of a 7.125 billion humans. That means Finns make up .0912% of the planet.

That's not 9%—that's point zero nine percent, less than a percent, less than a tenth of a percent. To put that another way, 99.9% of the planet are not Finns. How do we know this? Government censuses. Now, the best government censuses have a margin of error of at least 1%. So Finns make up .0912% of the planet, plus or minus one percent.

In conclusion: there is a 50/50 chance Finland doesn't exist.


This theory explains why Finland is metal AF, because when you're not sure whether you exist, you can't help but be metal AF. :mrgreen: Image

https://youtu.be/9crXKAIfAL0
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby Poodle » Tue Jul 18, 2017 6:20 am

Ah, wonderful! Takes me back to my loon-wearing youth when I had long flowing locks rather than a spreading bald top.

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Re: Why people can't math...

Postby Nikki Nyx » Tue Jul 18, 2017 3:46 pm

Poodle wrote:Ah, wonderful! Takes me back to my loon-wearing youth when I had long flowing locks rather than a spreading bald top.

That is one distinct advantage of being female. I still have long flowing locks.

I must admit to curiosity about the practice of loon-wearing, though. :mrgreen:
Image
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby Poodle » Tue Jul 18, 2017 4:43 pm


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Re: Why people can't math...

Postby Gawdzilla Sama » Tue Jul 18, 2017 4:49 pm

Nikki Nyx wrote:I find it salubrious to learn new vocabulary. It makes me smile, which automatically lifts my mood.

The beets were salubrious as well. :lol:
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The Myths of Pearl Harbor. Demythologizing the attack.
Hyperwar. Hypertext history of the Second World War.
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Re: Why people can't math...

Postby scrmbldggs » Tue Jul 18, 2017 5:05 pm

Poodle wrote:https://www.doyouremember.co.uk/memory/loon-pants


"Loon Outdoors Fresh Pants Cleans Deodorizes Sanitizes You and Fly Fishing Gear" :scratch:
Hi, Io the lurker.

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Re: Why people can't math...

Postby Poodle » Tue Jul 18, 2017 5:39 pm

Exactly - clothes which could do anything (a mantra of the 70s).




Not really!

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Re: Why people can't math...

Postby Nikki Nyx » Tue Jul 18, 2017 6:16 pm

Poodle wrote:https://www.doyouremember.co.uk/memory/loon-pants

I never heard that term before. We just called them "bell bottoms." As in...
https://youtu.be/MO2bExu2tGE
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby Gord » Tue Jul 18, 2017 7:09 pm

Nikki Nyx wrote:
Poodle wrote:Ah, wonderful! Takes me back to my loon-wearing youth when I had long flowing locks rather than a spreading bald top.

That is one distinct advantage of being female. I still have long flowing locks.

So do I, but they start at my shoulders: https://images.asadart.com/sources/com/ ... s/BC48.jpg
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Re: Why people can't math...

Postby Poodle » Tue Jul 18, 2017 7:20 pm

Nikki Nyx wrote:I never heard that term before. We just called them "bell bottoms."

Oh dear me, no! Bell bottoms flared from the lower knee. Loons flared from the upper knee. I thought simply EVERYONE knew that, dahling.
Actually, loons were just extra-wide at the bottom. If you wore them long enough, they'd cover your boots completely - thus picking up crap and water from the ground and abrading the bottom. That was the sign of a true cool dude.

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Re: Why people can't math...

Postby Nikki Nyx » Wed Jul 19, 2017 12:37 am

Heh heh... Well, what do I know? I was but a child in the Summer of '69. Still, I had a fantastic collection of hip-hugging bell bottoms and homemade granny dresses, plus hair down to my butt.
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby scrmbldggs » Wed Jul 19, 2017 12:41 am

:hmm: Gord, will you make that "down from your butt?" :-P
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Re: Why people can't math...

Postby TJrandom » Wed Jul 19, 2017 9:06 am

:lol: :lol: :lol:

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Re: Why people can't math...

Postby TJrandom » Wed Jul 19, 2017 9:09 am

.. no Hippy worth his salt ...


Were hippies ever worth their salt?

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Re: Why people can't math...

Postby Gord » Wed Jul 19, 2017 9:14 pm

scrmbldggs wrote::hmm: Gord, will you make that "down from your butt?" :-P

No the down from my butt is too coarse. You're better off with down from my face.
"Knowledge grows through infinite timelessness" -- the random fictional Deepak Chopra quote site
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Re: Why people can't math...

Postby scrmbldggs » Wed Jul 19, 2017 10:51 pm

:laff: Either way, that sounds cheeky. :-P
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Re: Why people can't math...

Postby Nikki Nyx » Thu Jul 20, 2017 12:20 am

:lol:
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby xouper » Thu Jul 27, 2017 10:54 pm

I've read the entire thread, and I did not see a definitive resolution of the key issue at the core of this problem.

Nikki Nyx wrote:I came across this on Facebook today. There was much heated argument over the solution to the following simple equation:
6 ÷ 2(2 + 1) = ?

One group insisted that the solution is 9. The second group, which included me, maintained that the solution is 1.

The first group did this:
6 ÷ 2(2 + 1) = ?
6 ÷ 2(3) = ?
3(3) = 9

Their explanation was that once the parenthetical addition is simplified, the 2(3) becomes implied multiplication, therefore the equation is solved from left to right.

My group did this:
6 ÷ 2(2 + 1) = ?
6 ÷ 2(3) = ?
6 ÷ 6 = 1

Our explanation was that the 3 remains parenthetical and, thus, takes precedence over the division in the order of operations, so that 2(3) must be solved before being divided into 6.

I've admitted that my math skills leave a lot to be desired, but I didn't think I'd forgotten them entirely. Would the math experts here weigh in, please?


Translation: What this question is really asking is what is the rule regarding operator precedence.

Lance correctly asserts there are two equally valid possibilities, and thus the person posing the question must resolve the ambiguity before an answer can be given.

My personal preference is to use the rule that results in an answer of 1.

However, the other rule is equally valid and is used, for example, by google's calculator.

As was observed previously, google's calculator uses the other rule and gives 9 as the answer.

https://www.google.ca/search?q=6+%C3%B7+2(2+%2B+1)

Why use a calculator? Because doing so will tell you what operator precedence rule it uses (as can be seen in the way google parses and expands the formula to remove the ambiguity).

Does that mean google's precedence rule is the correct answer?

No.

It would have been just as valid for google's programmers to have used the other rule, as long as it is clear to the user what rule is being used.

There is no correct answer to the original question as stated, because it is in essence asking which of the two rules is correct.

Answer: Neither rule is wrong. They are both correct.

Because of this ambiguity, it is the burden of the person posing the question to resolve it. It is not our burden to guess which rule was intended.

There is no default choice that all mathematicians will agree with.

Does this help?

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Re: Why people can't math...

Postby Gord » Fri Jul 28, 2017 12:05 am

Hi xoup! :wave:
"Knowledge grows through infinite timelessness" -- the random fictional Deepak Chopra quote site
"You are also taking my words out of context." -- Justin
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Re: Why people can't math...

Postby TJrandom » Fri Jul 28, 2017 12:09 am

Hi xoup... I`ll be good if you want to play in the sandbox... :wave:

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Re: Why people can't math...

Postby Nikki Nyx » Fri Jul 28, 2017 2:07 am

xouper wrote:I've read the entire thread, and I did not see a definitive resolution of the key issue at the core of this problem.

Translation: What this question is really asking is what is the rule regarding operator precedence.

There is no default choice that all mathematicians will agree with.

Does this help?
It does help, xouper, thanks. My answer was arrived at based on how I was taught, that parenthetical elements of the equation take precedence over multiplication and division. At the same time, I recognize that parentheses translate to "multiply by the parenthetical expression," and that multiplication and division have equal weight in the order of operations.

It's odd that we seem to lack a standard method of translating a symbol commonly used in an equation, and I wonder how this hasn't caused confusion amongst mathematicians. Personally, if I expected others to arrive at an answer of nine, I'd preface the parenthetical expression with a multiplication symbol.
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby xouper » Fri Jul 28, 2017 3:01 am

Nikki Nyx wrote:. . . It's odd that we seem to lack a standard method of translating a symbol commonly used in an equation, and I wonder how this hasn't caused confusion amongst mathematicians.


The ambiguous syntax in the original formula does indeed cause confusion among mathematicians. That's why they don't generally use that syntax unless it is abundantly clear what precedence rule is being used.

Most computer programming languages do not allow the syntax that was used in the opening post. If I were to speculate, I am tempted to think someone deliberately created an ambiguous question just to stir the pot.


Nikki Nyx wrote:Personally, if I expected others to arrive at an answer of nine, I'd preface the parenthetical expression with a multiplication symbol.


Exactly.

The same goes for the other answer of one, you'd be well advised to write the formula in a unambiguous way. But that assumes one recognizes the ambiguity in the first place, and that may not always be the case.

Newbie computer programmers often get tripped up by operator precedence. If there is any doubt, then add parentheses to force the precedence you want. There is no operational penalty for doing so.

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Re: Why people can't math...

Postby Nikki Nyx » Fri Jul 28, 2017 3:18 am

xouper wrote:
Nikki Nyx wrote:. . . It's odd that we seem to lack a standard method of translating a symbol commonly used in an equation, and I wonder how this hasn't caused confusion amongst mathematicians.
The ambiguous syntax in the original formula does indeed cause confusion among mathematicians. That's why they don't generally use that syntax unless it is abundantly clear what precedence rule is being used.
That's sensible, and neatly answers my implied question.

xouper wrote:Most computer programming languages do not allow the syntax that was used in the opening post. If I were to speculate, I am tempted to think someone deliberately created an ambiguous question just to stir the pot.
You know, I'll bet you're right. It seems like a "let's create Facebook drama" type of meme. Some people aren't happy unless others are upset. :roll:

xouper wrote:
Nikki Nyx wrote:Personally, if I expected others to arrive at an answer of nine, I'd preface the parenthetical expression with a multiplication symbol.
Exactly.

The same goes for the other answer of one, you'd be well advised to write the formula in a unambiguous way. But that assumes one recognizes the ambiguity in the first place, and that may not always be the case.
It certainly was the case for me! I had no idea how the others were getting their answer of nine until they showed their work. Then again, I did admit that my math skills left much to be desired. :mrgreen:

xouper wrote:Newbie computer programmers often get tripped up by operator precedence. If there is any doubt, then add parentheses to force the precedence you want. There is no operational penalty for doing so.
Again, sensible. I'm not a programmer; I only speak HTML, CSS, and Javascript for the purpose of designing a website, which I don't consider programming. I'm not really telling the computer what to do; I'm only telling it where I've stored graphics files and where on the page to display them, plus which graphics files to display when the mouse interacts with a specific area of the page in a certain way. If that makes sense. ;)
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein

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Re: Why people can't math...

Postby xouper » Fri Jul 28, 2017 4:36 am

Nikki Nyx wrote:I'm not a programmer; I only speak HTML, CSS, and Javascript for the purpose of designing a website, which I don't consider programming. I'm not really telling the computer what to do; I'm only telling it where I've stored graphics files and where on the page to display them, plus which graphics files to display when the mouse interacts with a specific area of the page in a certain way. If that makes sense. ;)


That counts as programming. I use all three in writing extensions for my firefox browser. (I'm also the code monkey for an award-winning non-profit website.)

Try doing something like this in javascript to alter the padding of an image, for example:

Code: Select all


<img id="mypicture" src="url" style="background: red;" />

<script>

var x = 6 / 2(2 + 1);    // not valid syntax

var e = document.querySelector("img#mypicture");

e.style.padding = x.toString() + "em";

</script>


And then try these two variants which will work (and be real obvious):

x = 6 / 2 * (2 + 1); // = 9

x = 6 / (2 * (2 + 1)); // = 1

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Re: Why people can't math...

Postby Austin Harper » Fri Jul 28, 2017 12:33 pm

xouper wrote:I am tempted to think someone deliberately created an ambiguous question just to stir the pot.

What?! A troll on the internet?! Impossible!
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Re: Why people can't math...

Postby xouper » Fri Jul 28, 2017 3:17 pm

xouper wrote:(I'm also the code monkey for an award-winning non-profit website.)


I forgot to add this disclaimer: Don't be impressed by that. It's a small obscure website and the annual award is easily something to sneeze at.

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Re: Why people can't math...

Postby Nikki Nyx » Fri Jul 28, 2017 7:50 pm

xouper wrote:
xouper wrote:(I'm also the code monkey for an award-winning non-profit website.)


I forgot to add this disclaimer: Don't be impressed by that. It's a small obscure website and the annual award is easily something to sneeze at.
Given that the overwhelming majority of websites are poorly designed, badly coded, and just plain ugly, I still consider it an accomplishment. I've lost count of the number of times I've just closed the tab because:
• the navigation was a nightmare
• the page lacked whitespace
• the color combination hurt my eyes
• the font choice was reprehensible
• the text layout was hard to read (centered, paragraphs all the way across the page, dense linespacing)
• there was too much Flash
• there was a sound file that played automatically
• they failed to slice their images, so they took forever to load
• there was no maintenance (dead links, blank pages, missing images, outdated info)
• no one edited the text (misspellings, poor grammar, incorrect punctuation)
That's just off the top of my head. A well-coded and well-designed website is a beautiful thing...and rare.
What are the facts? Again and again and again-what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history”--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!
—Lazarus Long, from Time Enough for Love, by Robert A. Heinlein


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