Alright, so math is a boring subject...but we can't deny the fact that it can be widely applied in many aspects of life. today, I'll introduce a simple magic trick that demonstrates how math can be applied.

The Binary Card Trick O_O

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Effect:
Ask anyone to call a number between 1 to 15, miraculously, you can pull out a card combination of such a number!

Math behind it:
Every number between 1 and 15 has a unique representation as a sum of some collection of the numbers 1, 2, 4, and 8. (To see which collection, just take the given number and successively subtract the largest number of 1, 2, 4, and 8 that is less than the given number. That number is part of your collection. The subtraction yields a new number; now repeat the process with this number, over and over, until you get 0.) The collection of numbers you obtain reveals the binary decomposition of the given number into sums of powers of two (in contrast to the usual representation of a number into sums of powers of ten).

Procedure:
Before the trick starts, pick an Ace, 2, 4, and 8 and put them on top of the deck, and then put the deck in your pocket.

Then when a number between 1 and 15 is called out, take the binary decomposition of the number, and use that to determine which of the first four cards you will pull out.

A technical trick with supernatural effects.
Ciao

Troy