Because it is assumed that you have tackled Nouns during Ch A & B, the CC curriculum uses the first week to review noun declensions in Lessons 1-6. The intention is that you use the week to focus on the concepts your student is weakest in, not complete every exercise. This can feel overwhelming. I have used each of the 4 days to highlight the important concepts and assigned exercises that will allow you to assess you understanding. Because the of the amount of content being reviewed this first week, the first 2 days of instructional videos are longer than they will be in future lessons, typically they will average 10 minutes.