First construct 4 five point stars either on the board or on a sheet of paper so that each player will be able to see the stars. Label the stars Star #1, Star #2, Star #3, and Star #4. In each star you will need to write numbers as follows:

STAR #1 --- 7,1,6,10,8
STAR #2 --- 10,9,6,7,5
STAR #3 --- 9,5,8,6,10
STAR #4 --- 7,9,4,8,10

Once you have prepared the stars you are now ready to play the magician. Ask a student to pick a number from one of the stars. Then ask them which stars contain the chosen number. If the student had picked the number 8. They would tell the magician that the number appears in Star #1, Star #3, and Star #4. The magician is then able to tell the student what number was picked.

Questions

• How is the magician able to do this magic?
  
• Would he be able to do this without looking at the stars (or memorizing anything about them)?
  
• How were the stars constructed.

answers .

You can also construct "Beat the Stars" using other mathematical procedures such as subtraction, multiplication and division. You might have to add more stars.

Activities/Projects

Be the magician in front of the class and see if they can discover how the magician does his magic. Have your students construct a similar magic act with more stars and larger numbers.

Have a student or group of students construct a "Beat the Stars" game where multiplying the star numbers produces the selected number.

NCTM STANDARDS

#6 Number System and Number Theory
#7 Computation and Estimation

KERA GOALS

#2.7 Understanding Number Concepts
#2.8 Computation related mathematical procedure

REFERENCE

"Bag of Tricks" 101 Instant Lessons for Classroom Fun!