The 3rd week of school just ended today, which also marks the end of my 3rd week student teaching. The program I am in requires one full school year of student teaching experience, so I will be with my mentor and students until May. I am in an 8th grade science classroom and today was my first "real day" teaching since my mentor was absent (a sub was present, but I had requested that he let me try managing the entire day.) My mentor had decided the students would do a round robin reading on a science packet, covering the scientific method. I implemented an incentive to all 4 of our classes that the class who behaved the most appropriately and listened/spoke at the right times would receive some kind of snack party in their period next week. I have tally marks on the board tracking the progress of each class. What I found is that two periods made it a point to be very attentive, engaged, and followed my directions, but my other two periods did not. They were chatty, messing around, weren't following the reading, and a whole bunch of other common scenarios I'm sure my veteran teachers are all too familiar with. I wrote an infraction for one student during a fire drill and he argued about it with me when we got back to class, students were pushing each other in the hallway, and I felt like the classroom was in a state of disarray for those two particular periods. My mentor is gone on Monday as well, so I will be the "main teacher" again, but after some reflection I realize that I need to get a better handle on managing behavior. I've read a few books this summer on the subject, but find that its easier to read something in a book than to put it into practice. What I'm looking for is any advice or suggestions to create a better classroom atmosphere. I am going to discuss these observations and reflections with my mentor on Wednesday when he returns, but I want to be set up for success for my day with the kids Monday. Moreso, I want to ensure I am set up for success the rest of the school year. Most of the kids generally respect me, but I am not sure if thats only because my mentor teacher is present. Any advice is greatly appreciated!  Should also mention that I am in a low-income school, and I know that most of my kids come from single-parent low-income households and a few of my kids are homeless. Not sure if this changes the way I manage this particular class, but I assumed it would be a relevant factor.