A Marine sergeant, having served his time in the Corps, took a job as a high school math teacher. Just before the school year started, he injured his back.
As a result, he was required to wear a plaster cast around the upper part of his body. Fortunately, the cast fit under his shirt and wasn't really noticeable. On the first day of class, he found himself assigned to the toughest students in the school.
These students, having already learned that the new teacher was a Marine, were leery of him and wondered how tough he really was. Walking confidently into his rowdy classroom, the new teacher opened the windows wide and sat down at his desk.
When a strong breeze made his tie flap, he picked up a stapler and promptly stapled the tie to his chest.
There was dead silence. He had no issues with classroom discipline after that.