In my ongoing effort to get caught up on my screencasts from the year, here is my screencast covering a side-by-side view of Classroom by Google with both the teacher and student view of the program. There are some items in it that I learned as I covered the sessions and answered teachers questions, so those of you who attended my first sessions on it would likely still learn something.
I had a teacher ask me if there was a way to hide or remove students who are no longer in your class. The answer is maybe. It depends on if they are officially dropped from your class and appearing as red in your roster and gradebook. If not, then no, you cannot remove them until they have been unenrolled from the class. If the student is showing up as red in your gradebook though, you can hide them so you don't have to worry about them. Here is a screenshot to help you do it: