Moving from Elementary to Middle School, I was bombarded with the craziness of how short a 45 minute period could truly seem. I needed a quick way to manage time, while simultaneously getting some things accomplished. This short PowerPoint is displayed via my projector every period for the first five minutes. Our passing periods are 4 minutes. I've set the first slide to fun those four minutes. While I'm in the hall doing duty, my presentation has begun. The students know that while slide #1 is up, they are still free to do what they choose to do. They can talk, visit, hang out... observe the classroom snake...whatever. When the bell rings, the slide will automatically switch to slide 2 (assuming that I started it at the beginning of the passing period).
Slide 2 has a 5 minute countdown along with a list of things "to do". It's my full expectation that every student have everything on that list complete. This slide is set to change at the end of the 5 minute countdown.
Slide 3 gives that day's topic/focus.
While that timer is going, no student is allowed out of their seat, other than to sharpen a pencil. No student is allowed to ask me questions, or come up to my desk. I am invisible and they have a job to do. Those that don't have the "to do" list complete... has a conversation with me after class as to why it's not done. My timer is going for the next period during that conversation.
I have had HUGE success with this simple tool. I hope you do too.