To Sir, with Love is a movie about a recent engineer (Mark Thackeray) looking for work. Mark Thackeray finds a teaching position at North Quay Secondary School. The school took in all the kids who were turned down from their previous school. Most professors are fed up with their antics but say they are mostly good kids who come from bad homes. Mark keeps a calm demeanor with his students.
After letting himself be upset by the students, he returns to the classroom with “a new approach to teaching his students and sets strict ground rules. The students will be leaving school and entering the adult world soon. His new strategy is to treat them as adults and allow them to discuss issues of their choosing. He emphasizes this by throwing out all their textbooks. As part of being adults, he insists the students will use proper forms of address (both toward him and amongst themselves) and take pride in their appearance and deportment”(https://www.imdb.com/title/tt0062376/plotsummary/)
The students return to their normal state. When Thackeray realizes that they are unexposed to the history and culture of their city, he proposes a class outing. The students have a great time and are starting to appreciate their teacher.
In gym class, a student (Carl Buckley) is forced to vault. All the students object, but he does it anyway. The vault collapses under breaks under his weight. Thankfully he is not seriously injured. Potter, another student in the class, threatens the teacher. Mr. Thackeray is forced to defuse the situation, he tells Potter to apologize, and with this statement is not invited to their dance, and almost loses the support of the class.
Thackeray receives a job offer during one of his lowest moments in the movie. He shows up at the dance, and all seems to be well. He was gifted a present from his class, along with a song. At the very end of the movie, we see him open his gift in his classroom. He takes his job offer out of his pocket and rips it up.