Explain that there is only one piece of gum left inside the pack and have a spectator freely select a row and a compartment. Display that the last piece is sealed inside the exact location they just chose.
Torn & Fuzed:
Show a silver pack of gum and a blue piece of foil from another pack. Visually make the blue piece fuse onto the silver foil, leaving it completely examinable and hand it out as an impossible souvenir
You mark one compartment of the gum pack as your prediction and have a spectator draw an X onto any compartment on the other side and it matches with your prediction.
Display a piece of gum inside one compartment. Have a spectator cup his hands underneath and visually push the gum through the compartment without any holes or slits.