How can a student tell which part of the lesson he or she is working on?

Imagine Math Lesson Activities consist of 4-5 parts (depending on the lesson): Pre-Quiz, Warm Up, Guided Learning, Practice & Post-Quiz.  A few lessons do not include Pre-Quizzes at the time (see article for more details).  

Students are able to identify which lesson activity they are currently on by using the progress bar located at the top of their screen.  When working on a lesson, they will see the below image: