Khan Academy is a website that offers free online math courses. The grade-level courses range from early elementary school to college-level mathematics. Users can also study by math topic, such as arithmetic, algebra or geometry.
Khan Academy's math courses include the most commonly taught topics in each grade or academic level. The lessons start with a video explanation of the topic, along with a blackboard demonstration of sample problems. Once the student understands the topic, he then completes practice exercises. If needed, the student can ask for a hint to help solve a difficult math problem. To keep track of progress, users can create an account, but this is not necessary for those who simply wish to work through the material without keeping a record.