Brings back high school memories. Students in teams had to expose in front of class about something I can't remember now. The thing is one of my group students got away with it in a stupidly clever manner. They showed a DIY "machine" where you put a coin in it and it gave something else instead from the tray. The thing is the "machine" in truth was the smaller girl from the team (who "couldn't attend school that day") into a cardboard box placed over the teacher's desk.
How the teacher didn't question its functioning? Why didn't he peek inside the cardboard box? It beats me, but it worked somehow. I have vague details because it was so long ago, but the girl should have been there at least between recess and the next class hour quiet and without moving inside that box.