At this point the case studies we have written and the materials we created to guide their use have been published [4], and they are being used in diverse ways in a significant number of institutions. They have been used as part of a first course in teaching and as the basis for a second course in teaching. They have been used as stand-alone materials and coupled with a book giving advice about how to teach, such as [5]. Just as learning mathematics is facilitated by well-thought-out exercises, our materials serve as a comprehensive set of exercises for teaching.