Show a die and two small empty cylinders with their lids. Ask a spectator to mentally choose a number from the die and have him put it inside the smaller cylinder and close this. Now, put it all inside the bigger cylinder and close it with its lid. Concentrate for a few seconds and, by reading it in the spectator's mind, reveal the chosen number. To finish, open the two cylinders and show to your audience that your mindreading was 100% correct.
Very easy to do.
All can be given for examination.