This in-class exercise is less formal than usual. I won't pass out paper copies, and I will not collect anything. We'll stop periodically during the slides for discussion.
While we won't do so in class, you should definitely work through Chapter 2 in Koskela in your favorite IDE. If you run into anything you're not sure about, post to Piazza. There are two goals here. First, learning TDD is best accomplished by doing TDD. Second, assignment 4 is exactly the same process as Koskela Chapter 2, except applied to a different problem.