A Mathematical Card Trick
Teach your fourth grader a fun magic trick! You'll need a deck of cards and some basic addition, subtraction, and multiplication skills. Your student will love the excitement of using magic and will have a great opportunity to practice his computation skills. Allow him to practice the trick on the whole family! After playing a few times, challenge your child to help you figure out why this trick works.
What You Need:
- Deck of playing cards
- Pencil and scratch paper (for computation)
What You Do:
- Find someone to trick.
- Ask that person to pick a card from the deck and keep it secret.
- Have them double the face value of the card (aces = 1, jacks = 11, queens = 12, and kings = 13).
- Ask them to add 3 to their result.
- Ask them to multiply this by 5.
- Have them add 1 if their card is a club, 2 if it is a diamond, 3 if it is a heart, and 4 if it is a spade.
- Ask them to tell you their number.
- To predict the card, subtract 15 from the final total. The right digit of the answer represents the suit of the card (1 = club, 2 = diamond, 3 = heart, 4 = spade). The left digit or digits is the number value of the card. For example, if their result is 83, the card is the 8 of hearts. If the result is 134, the card is the king of spades.
Can you figure out how this trick works?