Math Magic: A Card Trick to Practice Multiplication

Impress your child with math's magical powers with a card trick that uses math to do “magic.” Not only will your child have to do math just to have the trick performed, after you show him the trick's secret he'll want to be the biggest mathemagician around!

Materials

• All you need is a complete deck of 52 playing cards with no Jokers

What to do:

1. Have your child shuffle the cards as many times as he want. When he is finished, tell him to memorize the bottom card. Example: Ace of Hearts.
2. Ask him to put the deck on the table and turn over the top 3 cards.
3. Tell your child to deal cards face down below each of these 3 cards. He should start with the number on the face-up card (Aces = 1, Jacks = 11, Queens = 12, and Kings = 13), and then keep dealing cards until he gets to 15. For example, if the face-up card is a 9, he would deal 6 more cards to get to 15.
4. Ask him to keep the 3 face-cards on the table, and then put all the face-down cards on the bottom of the deck.
5. Have him find the sum of the 3 face-up cards. (Example: 9 + Queen (12) + 10 = 31) Tell him to deal out that many cards, can then put them on the bottom of the deck.
6. Explain that you have supernatural powers and that you can force any card to come out of the deck on you command. Ask your child for the name of his card so that you can command it to come out. He says, “It was the Ace of Hearts.”
7. Pretend to do some hocus-pocus as you say, “Ace of Hearts, come forth!” Repeat your command, and then look pleased with the result.
8. Your child, of course, won't see anything happen, but you insist that his card did come forth. Turn over cards off the top of the deck one at a time and say, “Here's the first card, here's the second, here's the third, and the Ace of Hearts comes fourth!” Turn over the fourth card and it will be your child's card!

The secret:

Each face-up card + counting up to 15 + the value of the card = 16. So? Well, 16 × 3 face-up cards = 48. Then 48 + 4 (come fourth) = 52 cards in the deck. So even though you didn't actually do magic this trick will seem supernatural since your kid will go from wanting to only see magic to wanting to know everything about math. Teach him how to perform it and how it's done through math and you'll have a practicing mathematician on your hands in no time.

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