homeGeek CultureWebstoreeCards!Forums!Joy of Tech!AY2K!webcam

The Geek Culture Forums


Post New Topic  New Poll  Post A Reply
my profile | directory login | | search | faq | forum home
  next oldest topic   next newest topic
» The Geek Culture Forums   » Other Geeky Stuff   » Ask a Geek!   » Hope you lot ain't seen this one already...

 - UBBFriend: Email this page to someone!    
Author Topic: Hope you lot ain't seen this one already...
spungo
BlabberMouth, a Blabber Odyssey
Member # 1089

Member Rated:
4
Icon 1 posted July 07, 2006 12:19      Profile for spungo     Send New Private Message       Edit/Delete Post   Reply With Quote 
This is mildly amusing. Took me two minutes or so to work it out, but then I'm old and slow these days. [Smile]

--------------------
Shameless plug. (Please forgive me.)

Posts: 6529 | From: Noba Scoba | Registered: Jan 2002  |  IP: Logged
Spiderman

Solid Nitrozanium Superfan!
Member # 1609

Member Rated:
4
Icon 1 posted July 07, 2006 12:24      Profile for Spiderman     Send New Private Message       Edit/Delete Post   Reply With Quote 
Mmmmm, mathematical trickery. [Smile]

Very similar to this: http://www.mysticalball.com/

I was called into the sales office the other day to explain how the link I just pasted works. These things are admittedly very clever...

--------------------
Math problems? Call 1-800-[(10x)(13i)^2]-[sin(xy)/2.362x]

Posts: 846 | From: Chicago | Registered: Aug 2002  |  IP: Logged
Grey_girl

Member # 2172

Member Rated:
5
Icon 1 posted July 07, 2006 12:50      Profile for Grey_girl     Send New Private Message       Edit/Delete Post   Reply With Quote 
So what's the trick?
Posts: 764 | From: NYC | Registered: May 2003  |  IP: Logged
Ashitaka

SuperFan!
Member # 4924

Member Rated:
4
Icon 1 posted July 07, 2006 13:18      Profile for Ashitaka     Send New Private Message       Edit/Delete Post   Reply With Quote 
There are only 9 possible answers to this problem. They all have the same symbol, and are divisible by 9.

--------------------
"If they're not gonna make a distinction between Muslims and violent extremists, then why should I take the time to distinguish between decent, fearful white people and racists?"

-Assif Mandvi

Posts: 3089 | From: Switzerland | Registered: Feb 2006  |  IP: Logged
Spiderman

Solid Nitrozanium Superfan!
Member # 1609

Member Rated:
4
Icon 1 posted July 07, 2006 13:59      Profile for Spiderman     Send New Private Message       Edit/Delete Post   Reply With Quote 
There's a bit more to it than that.

This relies on the magic number 9 again (7 Up puzzle comes to mind).

Take any number. 32 for example. This can also be expressed as 10*3 + 2.

With the game, it asks you to subtract the sum of the digits of the number from the number, which can be expressed as follows:

10*3 + 2 - (3 + 2) = 9*3 = 27

More generically: 10*a + b - (a + b) = 9a

As this number is always predictable, the symbols used are all the same, scattered throughout the myriad of other symbols which exist merely as a distraction.

They change the symbol each time you play, but they change *every* appropriate symbol. They only give you 10 seconds, but notice all the other symbols of the same type, and you'll notice they're all multiples of 9.

Again, very clever. The first time encountering this kind of puzzle can be flabbergasting.

--------------------
Math problems? Call 1-800-[(10x)(13i)^2]-[sin(xy)/2.362x]

Posts: 846 | From: Chicago | Registered: Aug 2002  |  IP: Logged
maybe.logic
Alpha Geek
Member # 5014

Member Rated:
3
Icon 1 posted July 10, 2006 07:35      Profile for maybe.logic     Send New Private Message       Edit/Delete Post   Reply With Quote 
quote:
Originally posted by Spiderman:
There's a bit more to it than that.

This relies on the magic number 9 again (7 Up puzzle comes to mind).

Take any number. 32 for example. This can also be expressed as 10*3 + 2.

With the game, it asks you to subtract the sum of the digits of the number from the number, which can be expressed as follows:

10*3 + 2 - (3 + 2) = 9*3 = 27

More generically: 10*a + b - (a + b) = 9a

As this number is always predictable, the symbols used are all the same, scattered throughout the myriad of other symbols which exist merely as a distraction.

They change the symbol each time you play, but they change *every* appropriate symbol. They only give you 10 seconds, but notice all the other symbols of the same type, and you'll notice they're all multiples of 9.

Again, very clever. The first time encountering this kind of puzzle can be flabbergasting.

It was'nt flabbergasting for me [tired] as it has never worked [ohwell]
Posts: 345 | Registered: Mar 2006  |  IP: Logged
Ashitaka

SuperFan!
Member # 4924

Member Rated:
4
Icon 1 posted July 10, 2006 07:46      Profile for Ashitaka     Send New Private Message       Edit/Delete Post   Reply With Quote 
It is really easy to blow peoples minds by doing square roots in your head, and believe it or not it is not very difficult. Most people today wouldn't even know how, without a calculator, to get a square root. Though it's been done in peoples head since the days of ancient egypt.


Here's my link on how to do it, though there are probably better explanations if you just google it.

How to do square roots in your head

--------------------
"If they're not gonna make a distinction between Muslims and violent extremists, then why should I take the time to distinguish between decent, fearful white people and racists?"

-Assif Mandvi

Posts: 3089 | From: Switzerland | Registered: Feb 2006  |  IP: Logged
canadiangeek
Geek
Member # 4946

Member Rated:
3
Icon 1 posted July 10, 2006 08:16      Profile for canadiangeek     Send New Private Message       Edit/Delete Post   Reply With Quote 
Ashitaka,

I didn't realize it was that easy... I feel like a shame to the geek community

Posts: 161 | From: Nova Scotia | Registered: Mar 2006  |  IP: Logged
maybe.logic
Alpha Geek
Member # 5014

Member Rated:
3
Icon 1 posted July 10, 2006 11:19      Profile for maybe.logic     Send New Private Message       Edit/Delete Post   Reply With Quote 
I second that, I just used to use factorisation, ooohh that was very boring!
Posts: 345 | Registered: Mar 2006  |  IP: Logged
dragonman97

SuperFan!
Member # 780

Member Rated:
4
Icon 1 posted July 10, 2006 11:29      Profile for dragonman97   Author's Homepage     Send New Private Message       Edit/Delete Post   Reply With Quote 
Personally, I've been meaning to learn this trick:
http://www.everything2.com/index.pl?node_id=1023392

If that's particularly slow to load, you can use the Google cache w/o images.

--------------------
There are three things you can be sure of in life: Death, taxes, and reading about fake illnesses online...

Posts: 9331 | From: Westchester County, New York | Registered: May 2001  |  IP: Logged
The Famous Druid

Gold Hearted SuperFan!
Member # 1769

Member Rated:
4
Icon 1 posted July 10, 2006 15:19      Profile for The Famous Druid     Send New Private Message       Edit/Delete Post   Reply With Quote 
Don't they teach the young geeks anything these days?

I was taught that square root 'trick' when I was 14, it's a natural outcome of a bit of very basic algebra.

(a+b)^2 = a^2 + 2ab + b^2

Using the numbers from the example, if you're trying to find sqrt(79), and your guess is 9, and you know there's a (smallish) error 'e' in your guess, then

79 = (9 + e)^2 = 81 + 18e + e^2

If e is small, then e^2 will be very small, so don't worry about it.

This leaves you with

79 = 81 + 18e
-2 = 18e
e = -2/18

so your approximate square root is 9 - 2/18

--------------------
If you watch 'The History Of NASA' backwards, it's about a space agency that has no manned spaceflight capability, then does low-orbit flights, then lands on the Moon.

Posts: 10669 | From: Melbourne, Australia | Registered: Oct 2002  |  IP: Logged
Ashitaka

SuperFan!
Member # 4924

Member Rated:
4
Icon 1 posted July 11, 2006 00:07      Profile for Ashitaka     Send New Private Message       Edit/Delete Post   Reply With Quote 
quote:
Originally posted by The Famous Druid:
Don't they teach the young geeks anythng these days?


No they don't. Well not in Indiana at least. My mother is a math teacher in a high school . She is not allowed to disallow 4 function calculators to her low students. Students don't even remember the multilication table any more becuase they never have to use it.

--------------------
"If they're not gonna make a distinction between Muslims and violent extremists, then why should I take the time to distinguish between decent, fearful white people and racists?"

-Assif Mandvi

Posts: 3089 | From: Switzerland | Registered: Feb 2006  |  IP: Logged
maybe.logic
Alpha Geek
Member # 5014

Member Rated:
3
Icon 1 posted July 11, 2006 03:33      Profile for maybe.logic     Send New Private Message       Edit/Delete Post   Reply With Quote 
That is a very good point Ashitaka, I have a few friends who have children doing A level maths, which is a decent level, and they can do all of the "theory" (via calculator) but ask them to try some mental arithmetic, they are about as advanced as a 10 year old, it is quite embarrassing to listen to the poor answers. [weep]
Posts: 345 | Registered: Mar 2006  |  IP: Logged


All times are Eastern Time  
Post New Topic  New Poll  Post A Reply Close Topic    Move Topic    Delete Topic next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:

Contact Us | Geek Culture Home Page

2015 Geek Culture

Powered by Infopop Corporation
UBB.classicTM 6.4.0



homeGeek CultureWebstoreeCards!Forums!Joy of Tech!AY2K!webcam