High School Math

MISSION STATEMENT: To encourage and promote a greater use of the internet and computer technology in the math classroom. For educators, students, parents and homeschoolers.

Thursday, October 30, 2008

Math Card Trick

Ask someone to choose a card.
Ask them to remember it's numerical value
(Ace = one, Jack = 11, Queen = 12, King = 13).
And also to remember the suit of the card.

  Tell them to
...double the value of the card.
...add three to the total.
...multiply the result by five.

  Now, tell them if the card is
...a diamond they must add one.
...a club they must add two.
...a heart they must add three.
...a spade they must add four.

Ask them for their final total.
And tell them their card from their total.

  The Secret:
The total will have two or three digits.
Mentally subtract 15 from their total.
The last digit gives the suit
(diamonds 1, clubs 2, hearts 3, spades 4.)
while the first number(s) gives the suit.

  Example: Jack of clubs
11 doubled is 22, add 3=25,
multiply by 5=125, add 2 for clubs=127.
Subtract 15 mentally, the result is 112.
Last number (2) means clubs,
first number (11) means Jack.

More Stuff at www.TheMathWebSite.com.