We're removing Missions in June 2020. See here for more information.
Khan Academy tracks mastery on a skill-by-skill basis. When you first start using Khan Academy, you’ll be at the Needs Practice level on every skill. As you answer math problems, Khan Academy’s adaptive software learns what you know and adjusts your mastery level on each skill.
We encourage you to make Mastery your goal!
Note: It is possible to move backward in levels by answering questions wrong. Keep practicing to keep your mastery level up!