If you have to check whether the teacher’s looking, you already know the answer.

The glance is the verdict, delivered before any thinking happens. You do not check the room when you are doing something you are entitled to do; the head movement is your own judgement arriving before your reasoning. Anything that requires surveillance management is already classified in your head.

Treat the impulse to check as a stop sign rather than a hurdle to get past. When you notice yourself scanning, put the pen down for a second and decide deliberately. You will be right about it more often than any rule you could memorise.