PRESENTATION

Ask a friend to pick any number within the circle. Explain that you are going to point randomly at different numbers in the circle while he silently counts up to 20. Tell him to start with the number he has picked and add one every time you point to a number.

Example:
Your friend has picked the number 9, so he counts 10 when you point to the first number, 11 when you point to the second number. When he gets to 20, he should say, "Stop!", and you will be pointing to the number that he is thinking of!

HOW TO DO IT

As your friend is counting to 20, you are also counting. The first seven number you point to can be any number in the circle. However, the eighth (8th) number you point to must be 12. Then point backwards with the numbers (eg. 11,10,9,....) until your friend tells you to stop.

This is a table of reference on how your friend counts and what you count.
(For example if your friend has picked the number 9)

Have fun with this free magic trick.