The Piano Trick
The Piano Trick  works well for schools, young people seem to really enjoy this. It is interactive therefore you will need a good supply of cards, 21 cards  per participant. It is self working and really easy to perform. When used for schools it is a good way to get the students thinking outside the square. You can ask your students if anybody can  fathom out the secret and explain it to the class.
Presenters of  the fully inclusive package will get this download included