There are five levels of mastery for each exercise:
- Needs Practice
- Level One
- Level Two
When you first start using Khan Academy, all topics are at the Needs Practice status. You will immediately go to a Warm-Up with some questions from the Mission you selected. If you answer these initial questions correctly, you may immediately receive some Mastery Challenges. Otherwise, you'll need to start practicing each exercise that has a Needs Practice status.
To go from Needs Practice to Practiced, you need to answer a certain number of exercises correctly without using any hints. Usually, it takes five correct answers in a row to advance; if you get a question wrong, your progress toward five-in-a-row will start over. Once you satisfy the condition, you earn the Practiced status.
After you are Practiced in an exercise, moving up to the next level works differently. To keep moving up, you must perform a Mastery Challenge. This challenge may not be available immediately after you finish practicing an exercise. Khan Academy will show you a timer that counts down the time until the next Mastery Challenge is available.
Once the Mastery Challenge becomes available, it will give you one question from several different topics. You cannot choose which topics are part of the Mastery Challenge, Khan Academy selects them for you. If you answer a question correctly, you will move up at least one level in that topic. For example, if you were at Practiced (light blue), you'll go up to Level One (a little bit darker blue). If you were at Level One, you'll go up to Level Two. If you were at Level Two, you'll advance to Mastery! But watch out, because if you get an exercise wrong, you might actually move down a level.
If Khan Academy thinks you already know a topic very well, either because you've mastered more difficult topics in the same subject or you did really well on your practice questions, it may move you up two levels instead of one!
After you've mastered a topic, you may continue to see its questions in your Mastery Challenges. These help you to review challenges and retain the information you've already learned. If you answer the question incorrectly, you may move down a mastery level. However, if you keep answering the review questions for a topic correctly, they will come less frequently during your Mastery Challenges.
If you get a question with an exercise you've never practiced, don't panic! Khan Academy is giving you an extra-difficult question because it thinks you may be ready for it. This is called a Cascading Challenge. If you don't know the answer, you can always click "I haven't learned this yet" to keep moving through the Mastery Challenge. If you are able to answer the question correctly, you may get to move up two levels!
In addition to Mastery Challenges, you may also see a Booster Challenge. These are given in place of Mastery Challenges sometimes if Khan Academy thinks you already know most of the topics in a mission. To learn more about the Booster Challenge, follow this link to the "What is a Booster Challenge?" article.