# Calling all math whizzes !



## fish7days (Jul 30, 2005)

Pleez esplain......

http://www.gujaratplus.com/cball/middle.html

Thx

André


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## Dewmazz (Sep 6, 2005)

My friend and I did this once. We found out that it all revolves around factors of 9. For instance, look at 72. The symbol changes each time, but the numbers that _aren't_ factors of nine stay the same, so it's inconspicuous. Flash animation is amazing.


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## hir0 (Nov 11, 2005)

i did it a few times in a row with the same numbers. the thing only worked once.


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## Dewmazz (Sep 6, 2005)

Are you following the directions right? It should always work...
hmm...


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## JerseyScape (Nov 18, 2005)

I just did it 5 times and it worked perfectly.

Example for people that are confused on the directions.

Choose any two digit number (I'll pick 11)
Add together both digits (1 + 1 =2)
Subtract 2 from 11 and you get 9
click big blue circle and see that the symbol that comes up is corresponding to your number.

this thing is amazing


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## bossteck (Oct 12, 2005)

I am no maths wiz but let me try to explain this.

Suppose you picked 2 digits, let the first be X and the second digit be Y.

You are suppose to use [10X + Y] - [X +Y] 
(e.g. X=2, Y=3, you will be using 23 - 2+3, 23 is actually 10x2 + 3)

[10X + Y] - [X + Y] will give you 9X

Now, that's how we get the factor of 9. 
X can be any single digit number (0 to 9), so 9X will be 0, 9, 18, 27, 36, 45,54,63,72 or 81 (multiples of 9)

If you were to look at the symbol list again, you would have noticed that the symbols for the multiples of 9 are all the same!! The rest of the symbols and numbers are just decoys.

hiRO: The reason why you noticed that it didn't worked is because you didn't followed the instructions and use 10X+Y - X+Y.

cheers!


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## Dewmazz (Sep 6, 2005)

Um, yeah. What he said.


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## niko (Jan 28, 2004)

This animation seemed amazing to people like me that don't realize certain simple mathematic facts. (Adding the two digits of a 2-digit number and subtracting the result from the original number produces a result that is divisible by 9.)

The "ball" doesn't display the actual final number. It has no way of knowing it. It always displays the symbol that corresponds to the number 9.

And of course - all numbers divisible by 9 (9, 18, 27, 36...) have the same symbol 

Every time you play again the corresponding symbol for the multiples of 9 changes but all of them get the same one.

So clicking the ball does nothing but show the symbol that is assigned to the number 9.

I guess you can play this game without a computer. Just ask your victim to add the 2 digits, subtract them from the original number, and divide by the first of the 2 digits of the original number. The answer will always be 9. 

Do I qualify as a math wizard now? Where is my cookie then?

--Nikolay


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