I was curious to see how many teachers do this. As a first-year teacher, I've found that keeping the kids busy every day the entire class period is essential to classroom management. There is less down time; hence, less time for in-class shenanigans and talking. I also look at it this way: These kids have 43 minutes with me, which comes out to under 40 when you factor in attendance, grading, handing back homework, etc. I need to maximize every minute I can, and I do. Although it is a challenge sometimes, I will keep teaching "bell to bell." I just don't see the value in giving kids 10 minutes at the end of class (as some do) to waste time. I'm there to teach, not hang out.