To perform a trick.
12 hardwood cards will perform an amazing math trick. Similar to the Brainiac 9 cards, but more complex as many possible answers can occur (over 300). The effect is that you ask someone to select 3 sets of 3 different color cards and you will be able to tell them the sum total of the 3 sets of numbers. To perform the trick: Turn all cards over so that you cannot see the numbers. Ask someone to pick 1 card of each color and put them in a row, face down. Then ask them to pick from the remaining cards and do the same. Repeat this process one more time until you have 3 rows with 3 cards each laid out. (NOTE: There will be 3 cards left over which you can remove from the playing field – which you can leave face up to make it easy). While your back is turned, have them turn their cards over, exposing the numbers. Each row will create a 3 digit number. Have them add the three, 3 digit numbers together and write the number down. While they are adding, you write a numbers down on your paper and your numbers will match. The Secret: Recall that you looked at the 3 remaining cards that were not chosen. Put them in the same color order as the layout of the 9 cards. Now subtract that 3 digit number that it forms from 1665 and you will get the same number!!