The Khan Academy website, app, and corresponding YouTube channel were founded by Salman Khan, who holds degrees in math, engineering, computer science, and business. The content is designed for self-paced learning, and, in general, it's a solid resource to supplement classroom instruction on basic math skills. Sal's uncanny ability to explain the most basic and complex subjects in these brief videos is impressive, engaging, and educational to boot. But Khan Academy isn't a standalone math course. The videos tend to be more procedural than conceptual and may, at times, contain minor inconsistencies that could confuse some learners. But videos on the "why of algebra," and some of the older videos have been updated with more polished instruction. High school-age kids are most likely to find the site useful and appealing.
The site is continually growing -- math lessons for grade-schoolers were added recently, and items about science, computing, history, and other topics are also available. Updates include collaborations with the Stanford Medical School, and even math and science explorations with NBA star LeBron James. The dashboard has improved over previous versions: Lessons are recommended based on progress, and navigation is easier. A companion iPad app allows video downloads for offline viewing to reinforce topics or practice ones that kids maybe struggling with, and there's even a new version of the site in Spanish. There's also a new Coach Resources section, aimed at parents, tutors, and teachers, with helpful tutorials on using the site. Parents and tutors may find some of the case-study videos particularly useful in helping kids get the most out of the site. Based on its popularity, the site is likely to keep growing. As Sal has said, "What you see today at Khan Academy is a very crude approximation of where we'll be in five or 10 years."