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Monday, August 7, 2006

What the Mathematicians? Mind-Readers? Can Someone Please Tell Me How the F*** This Is Happening?

Posted by CHRISTOPHER FRIZZELLE on August 7 at 16:24 PM

OK. Go to this website.

Follow the instructions—easy:

(1) In your head, choose a two-digit number.

(2) Add the two digits together, then subtract that sum from your original number. (So, if your orginal number is 23, you subtract 5 from 23.)

(3) Whatever number you come up with, stare at the corresponding symbol on the screen. Keep staring for about 10 seconds. You’ll see.

Freaky, right?

I’ve done this again and again. I even did it with Brendan Kiley just now, and we both choose our own numbers and didn’t tell each other what they were, and it worked for both of us simultaneously. The only logical answer we can come up with is that the computer is reading our minds.

Someone with a math degree please get in the comments and explain this to me.

UPDATE: All is explained in comments. It’s not as exciting as you may have hoped. The computer is not reading your mind. As you were.

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1

All the numbers divisble by 9 have the same symbol. All results of their algorithm are divisible by 9.

Posted by Steve | August 7, 2006 4:29 PM

2

Steve, talk to me like I'm a two-year-old. I don't understand what you're saying, because I've done it a lot of times and the symbols change.

Posted by christopher frizzelle | August 7, 2006 4:32 PM

3

Christopher-
All of the numbers that are divisible by nine have the same symbol. If you try it more than once, the game rotates the symbols, but all the numbers that are divisible by nine still have the same symbol.

Posted by Cori | August 7, 2006 4:35 PM

4

Wait, I picked 11. 1 + 1 = 2, -10 = -2, then it showed me the symbol for 9 and cackled at me. That sucked.

Posted by Dougsf | August 7, 2006 4:40 PM

5

Sorry I mean -8. I may suck at math, but it still sucks.

Posted by Dougsf | August 7, 2006 4:40 PM

6

didn't you notice christopher that 9 18 27 36 .... all have the same sign attached to them? it's impossible, i think to have a number NOT divisible by 9. spooky math world!

Posted by terry miller | August 7, 2006 4:42 PM

7

11 minus 2 equals 9.

Posted by christopher frizzelle | August 7, 2006 4:43 PM

8

dougf: 11 - (1+1) = 11 - 2 = 9

Posted by dna | August 7, 2006 4:44 PM

9

Oh, I guess I can't follow instructions well either, it was making a spooky noise at me here at my desk so I was trying to speed through it.

Posted by Dougsf | August 7, 2006 4:52 PM

10

Christopher: all the answers are 9 or 18 or 27 etc. Try it. 10-(1+0)=9; 11-(1+1)=9; 12-(1+2)=9; 13-(1+3)=9; 14-(1+4)=9; 15-(1+5)=9; 16-(1+6)=9; 17-(1+7)=9; 18-(1+8)=9; 19-(1+9)=9; 20-(2+0)=18; etc.

All of the multiples of nine have the same symbol. It's different every time you play the game, but the nines are always identical to each other. Since every two digit number results in a multiple of nine, the symbol for your result is known in advance.

Posted by Fnarf | August 7, 2006 4:57 PM

11

If you thought THAT was fun...

1) Think of a five digit number
2) Add up all of the digits
3) subtract that sum from the original five-digit number
4) now choose a number that isn't "0" from the result to "X"
5) tell me the remaining digits
6) I'll tell you which number you chose to "X"

Take this brother may it serve you well.

Revolution 9.

Posted by matthew fisher wilder | August 7, 2006 5:03 PM

12

The best part is, you can tell your friends that it will get your original number right EVEN IF YOU DELIBERATELY CONCENTRATE ON THE WRONG NUMBER! It knows you're lying!

Maybe if you're lucky you can get them to admit to stuff now that they know they can be read.

Posted by Fnarf | August 7, 2006 5:04 PM

13

Math does a body good.

Posted by matthew fisher wilder | August 7, 2006 5:04 PM

14

Since no one has posted the algebraic proof... A two digit number, ab, is really a * 10 + b (eg. 72 = 7 * 10 + 2).


So step 2 is:

original number - sum of digits

= (a * 10 + b) - (a + b)

= 10a + b - a - b

= 9a


No matter what your original choice of number, the answer will always be a multiple of 9.

Thishasbeenapublicserviceannouncement...

Posted by Monkey | August 7, 2006 7:52 PM

15

God bless you, Monkey.

Posted by Fnarf | August 7, 2006 9:10 PM

16

math is your friend.

Posted by seattle98104 | August 7, 2006 9:53 PM

17

You guys, there's no such thing as math. Silly boys.

Posted by Hollywood | August 8, 2006 11:09 AM

18

Tennis stars photos here: <a href=http://tennisstars.info>Tennis Stars</a>

Posted by Tennisstars | August 24, 2006 9:41 AM

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