I once compared notes with another teacher who had long since left the field and gone on to become an electrician. He told me he got a real charge out of it and found it more relaxing than teaching. Now, ten years later, I believe him.
Once a year, he played a joke on the kids of his class. When they were waiting to go into the room, he would stand in front of the door and say, “What is the password? To enter, you must give me the password.” Naturally, they all came up with the typical things like “Please” or “Abracadabra” or something like that, but the answer was more obvious. The password was given in the initial question: “What.”
I turned that into a yearly gag to play on the kids and decided to use a similar game for a CAT. A few times a week, I brought out a flash set of flash cards or had an open-ended question that had to be answered to get into the class. A correct answer to a flashcard or a reasonable answer to an open-ended question gained them entry into the classroom. This only took a few minutes to do, and I quickly learned which students had a skill and which needed reteaching. If I used an open-ended question, I quickly had everyone’s opinion of the matter.