No Cheating!
À big challenge for teachers nowadays is to keep students from cheating on exams. Almost all students carry a supercomputer in their pockets with collective world knowledge at their fingertips. It’s much too easy to cheat. On exam days, this teacher creates a name slot on the chalkboard for each student to place their cell phone as they are walking into class.
This way, he can be sure that no cheating will happen during the exam. The names and keeping the phones in plain sight helps keep the students from panicking about getting their phones back. Not such a bad idea, teach!