Math Magic Tricks

Young people always seem to be amazed with math magic tricks! So it's almost a no-brainer to use math tricks to get kids excited about learning math!

Materials: A willing subject, Pencil, Piece of paper, Calculator is optional. Doing the math by hand will help kids build math skills!

• Ask someone to pick a number between one and ten.
• Multiply that number by 2.
• Add 5 to your answer.
• Now multiply that total by 50.
• Add 1752 if the person already had their birthday this year or add 1751 if they haven’t had it yet.
• Next, subtract the person’s year of birth. Be sure you use a four-digit number like 1990 for the year.
• Wave your hands over the paper (or calculator) like a magician and reveal the magical three-digit number. The first number is the same one the person originally chose and the last two are their age!

• Start with two dice. Have your subject roll the dice and then stack them one on top of the other. Now there are 3 numbers you cannot see:
  • the bottom of the top dice
  • the top of the bottom dice
  • the bottom of the bottom dice

• Make a point to let the person know that you can't see those faces of the dice. Here is where the math magic comes in.
• Tell them you'll be predict the sum of the three hidden faces. In your head subtract the top face of the two dice from 14. This is the number that the other three will add up to. For example, if the top number is 6, the other three will add up to (14-6 = 8) 8! Pretty Cool!
• You can do this with three dice also. Instead, just subtract the top number from 21.