Your audience will believe that you really do possess mindreading ability after they've witnessed this incredible mental test!
You freely show a blackboard slate that has been divided into six spaces, consisting of two horizontal rows of three spaces each. Ask a volunteer to concentrate on a single thought. It could be their telephone number, a relative's name, a favorite color --- anything at all.
You appear to focus on their thoughts and write down a prediction in the upper left-hand section of the slate. Your prediction is covered by a piece of card, and turning the board to face the spectators, you ask the participant to call out his thought. You write this immediately below your covered prediction.
This same procedure is carried out with two more random spectators --- one might look up a word in a book, the other freely selects a playing card. Always, your predictions are written on the upper portion of the slate before writing the spectators' choices underneath. To prove your ability, the covers are removed from your predictions in full view of the audience. It is seen that you are 100% accurate in all three of your premonitions!
A seemingly impossible effect, yet one which is so very easy to do thanks to the excellent equipment supplied! You'll knock out any group with this one.