Every course contains supplemental materials that can be accessed from the Student page (whether you are a teacher or student).
To access Supplemental Materials scroll down past the main course modules until you see "Supplemental Materials."
Press the green arrow button to view the modules in that course's Supplemental Materials section.
Every main course on CodeHS contains Supplemental Materials, which are a great way for advanced students to gain extra practice with more challenging concepts.
Also, on CodeHS Pro teachers can customize which modules appear in the Main and Supplemental sections of a course, giving great control over course customization.