We all know that you need to keep a second gradebook from the one your school uses. We also know that a gradebook on paper is susceptible to a lot of wear and tear with erasing, and lugging back and forth between school... It also can't calculate averages for you!
So, I am sharing my excel gradebook that I use to keep track of all 5 of my classes. There are three sections on each page: tests, quizzes, homework. Under each column the averages are calculated and then appear on the cover page that allows you to compare your classes side by side, assignment by assignment.
For the cases where you teach more than one prep (which I do every year), you can save two gradebooks based on the subjects. Ex. Algebra Gradebook, Geometry Gradebook. That way you're not comparing separate classes!
Hope you enjoy as much as I do!