Tell your friends that you have eleven fingers, and you can prove it!

1. Using your left forefinger, point to each finger of your right hand, counting "One, two, three, four, five".

2. With your right forefinger, count the fingers on your left hand, "Six, seven, eight, nine, ten".

3. Say "Funny, I'm sure I had eleven. Let me count them again."

4. This time, count backwards, pointing to the fingers of your left hand, say "Ten, nine, eight, seven, six...". Then stop, hold up the right hand and say "Plus five equals eleven! I told you I had eleven fingers."