Help Center
Community
Report a Problem
Sign in
Menu
Help Center
Community
Report a Problem
Sign in
How can we help?
Khan Academy Help Center
Learners
The Mastery System
Understanding the Mastery System
Understanding the Mastery System
Why can't I start a Mastery Challenge over?
What are Course and Unit Mastery?
What are Mastery Challenges?
How does new content affect mastery goals?