As a first year teacher and a relatively reserved person, one of my biggest fears this year was having to discipline the students if they misbehaved. What I've learned is that for the most part, misbehavior is not inherent to the students, but inherent to the teacher's ability to engage the students. It turns out that the classes with the fewest discipline issues are the ones that are the most interesting and thought-provoking. If the students are all paying attention to the lesson or working diligently on an assignment, they don't have the opportunity to be disruptive.
Last week I had a small problem with students talking during class while other students were still working on an assignment. When I confronted the group of students and asked them why they were talking, one of them replied, "well, we're done already..." At the time I chastised them and told them, "just because you are done, doesn't mean you have the right to disturb others." But the more I thought about it, the more I realized that students are inevitably going to chat or lose their concentration if they aren't kept active. To combat this, I decided to give them an ongoing extra credit assignment that they can work on whenever they have free time in class. It consists of 10 questions ranging from logic problems to riddles to Sudoku puzzles to difficult math concepts we have covered in class. The students responded quite favorably to the challenging questions, the opportunity to gain extra credit, and the possibility of figuring out the questions before their friends.
Here's one of the problems I posed to them, see if you can get it: