Khan Academy is a free Online Courses, Lessons & Practice. Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. I use Khan Academy to practice my math by practicing the exercise and watch the video tutorials. I also use this online course to practice my SAT test. On Octuber 14, I did my first Pretest SAT. My score was unexpected and I’m glad to use this website as my learning tool.