Face up, face down card trick revealed

This is a simple and easy to do card trick. All you need are 12 playing cards and the trick is to bring cards from behind your back with the same number of cards faceup without looking.

FACEUP, FACE DOWN

The props: Twelve cards

The magic: Without looking, you’ll be able to bring cards from behind your back with the same number of cards faceup in each hand.

1. Take 12 cards and then deal them into a pile, all face down.
2. Tell your audience, “I’m going to turn some of these cards faceup,”and as you do, quietly make sure you turn exactly half the cards faceup. Then mix all the cards in the pile—you can do this yourself, or tell someone in the audience, “Go ahead and mix the cards.”
3. Deal the top six cards into a pile, leaving six in your hand.
4. Then pick up the pile on the table in your other hand, and put both hands behind
your back.
5. Tell your audience, “Now, without looking, I’m going to magically arrange the cards to have the same number of cards faceup in each hand.”
6. With both hands still behind your back, flip one set of cards over.
7. Bring out both hands and spread out the cards as you show that each set has the
same number of cards faceup.






Trick revealed

Why does flipping one set of cards give the same number of cards faceup in each hand?

This magic trick relies on a simple trick of subtraction, and on hiding the steps that make it work.

Of the twelve cards, you turned six faceup, without drawing attention to how many you turned over. After you mixed them up and dealt six cards into a pile, you probably had some of the faceup cards in that pile—let’s say you had four of them.

That mean that in the other set, you had two cards faceup (six minus four). Since
each set has six cards, having two cards faceup means you had four cards face down.
Flipping the set will give you four cards faceup in each hand.

If the trick didn’t work for you, some of the cards probably turned over when they
were mixed—you need exactly six up and six down when you move your hands
behind your back.

You’ll find that this trick also works if you start with 14 cards, or 16 cards, or any even number. Just make sure that exactly half the cards are faceup for the trick to work.

Source: California Science Center