Cards have their face value. Jack is 11 Queen is 12, and King is 13
1) Deal piles of cards face up.Starting with value of first card, deal out till #13 is reached, then start a new pile. ie:if the first card is a 7, deal out 6 more cards on top of it.
2) At end of this step, the cards that cannot complete a 13 card pile are temporarily set aside
3)Turn all completed stacks face down
4) Tell subject to pick out any 3 piles. Place the other cards with the ones that were set aside in step 2
5) Tell subject to turn the top card of ANY 2 of the piles face up
6) After step 7, announce value of the top card of the third pile
7) Add the values of the 2 upturned top cards. MENTALLY add 10.. Now,with the discarded cards, mentally count out this derived number.. The number of remaining cards represents the value of the top card of the third stack