Swords of Truth

An astounding magic trick done with math.  This is based on math magic from the book, the “Collected works of Alex Elmsley” by Stephen Minch.  The 8 different alder wood swords are very cool and give the trick a nice flare.  Each sword has 6 different numbers on it.  (48 different numbers in total are used by all swords).  Each sword is about 5 1/2" long and 1/4" thick.  They will come on strung on a chain for your convenience.

Let a spectator select one of the swords and then a number on that sword, keeping that number a secret. You can even have up to 8 people select a sword at random.

Then have them simply indicate the shapes (square or circle) surrounding the numbers on the sword, but they must lie about the shape surrounding the number they chose.  At no time do they say aloud any numbers and at no time during the trick are you able to see the swords.  Astonishingly, you will be able to correctly name the number(s) chosen.

I will not reveal the details of the math secrets here, but as a hint, simple binary codes are established when they tell you the shapes and you will easily be able to determine the number.  This is a GREAT fun item at gatherings. 
I think 12 yrs old and up can do this, and perhaps younger if a bit advanced for their age. Its a good item for math teachers also, as it demonstrates in a fun way the use of binary math.
Designed and made in Spring Hill, FL.