Khan Academy is constantly adding new content to the library, and we're happy to say that we've updated the corresponding course and unit mastery systems to reflect the latest updates.
This means that your course or unit mastery goals may have changed, as the number of skills in each lesson, unit, or course may have increased.
Each new skill added to the course or unit will increase the mastery goal by 100 mastery points. Don't worry, you'll still have mastered the same number of skills as before, you'll just have additional ones to complete now, which means you'll have an even better understanding of the subject that you're working on!
We're always working to improve our math mastery systems and, while it is an unfortunate side effect to see the goal rise when we add new content, we try to make these changes when our users will be affected the least in order to minimize disruption to the classroom. We recognize this still isn't ideal for students, so if you have any ideas or feedback for other ways we could approach this situation, we'd love to hear them!