The specific steps are as follows:
1, preparation stage: put on your shirt and button it. First take a biscuit, break off a small piece, and then hide the remaining large piece in the shirt between two buttons on the abdomen, while the broken piece is hidden in your hand by the method of "edge grid" (that is, put it horizontally behind a finger, hold the edge with your finger, and block the biscuit with your finger).
2. Debris mixing: Sit at the table and break a biscuit naturally. In this process, use the palm cover or line of sight transfer technology to find a machine to throw the debris hidden in your hand into the debris pile.
3. Forced selection: It seems that the pre-prepared fragment just mixed in and another fragment of similar size are randomly selected for the audience to choose one. If the spectator chooses a piece prepared in advance, let him keep this piece and put the other piece back in the chess pile. If the audience chooses another piece, let them put it back in the debris pile, leaving the prepared pieces. In short, no matter how the audience chooses, the result is the same.
4. The final performance: eat the whole piece of debris, then pretend to take it out of your stomach, take the big biscuits hidden in advance out of your shirt, and splice them with the small pieces left in advance. These two pieces were originally made of a biscuit, which can fit perfectly. So there is a performance effect.