# How does this Crystal Ball thingy work?

**URL:** <https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683>\
**Category:** Factual Questions\
**Created:** [June 23, 2003, 3:10am UTC](https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683 "2003-06-23T03:10:12Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Batsinma\_Belfry](https://avatars.discourse-cdn.com/v4/letter/b/ea5d25/32.png) [@Batsinma\_Belfry](https://boards.straightdope.com/u/Batsinma_Belfry)\
**Post date:** [June 23, 2003, 3:10am UTC](https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683/1 "2003-06-23T03:10:12Z")

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[Crystal Ball](http://mr-31238.mr.valuehost.co.uk/assets/Flash/psychic.swf)

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**Author:** ![Larry\_Griffin-Kentzel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/larry_griffin-kentzel/32/14787_2.png) [@Larry\_Griffin-Kentzel](https://boards.straightdope.com/u/Larry_Griffin-Kentzel)\
**Post date:** [June 23, 2003, 4:01am UTC](https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683/2 "2003-06-23T04:01:33Z")

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Since this has a factual answer, I’ll move it to GQ for you.

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**Cajun Man** ~ SDMB Moderator

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**Author:** ![Captain\_Gutgore\_Blooddrink](https://avatars.discourse-cdn.com/v4/letter/c/c5a1d2/32.png) [@Captain\_Gutgore\_Blooddrink](https://boards.straightdope.com/u/Captain_Gutgore_Blooddrink)\
**Post date:** [June 23, 2003, 4:05am UTC](https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683/3 "2003-06-23T04:05:17Z")

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Once you add the sum of any two didgit number, and the subtract that sum from the original, it’s always a multiple of nine.

The only possible numbers are:

81  
72  
63  
54  
45  
36  
27  
18  
9

And those are always the same symbols

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**Author:** ![Loopus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loopus/32/15343_2.png) [@Loopus](https://boards.straightdope.com/u/Loopus)\
**Post date:** [June 23, 2003, 4:17am UTC](https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683/4 "2003-06-23T04:17:55Z")

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Your link is taking forever to load for me, but it sounds like the same thing Snopes describes [here](http://www.snopes.com/humor/iftrue/psychic.htm).

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**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\
**Post date:** [June 23, 2003, 4:45am UTC](https://boards.straightdope.com/t/how-does-this-crystal-ball-thingy-work/183683/5 "2003-06-23T04:45:29Z")

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Others too have wondered this:

[http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=163712](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=163712)  
[http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=169075](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=169075)  
[http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=166356](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=166356)