Maybe you want to update your current skills. Maybe you’re struggling to understand your math class. Maybe you’re trying to help your child with her homework. If so, you might want to check out these resources for free math and science lessons.
Khan Academy is a non-profit “changing education for the better by providing a free world-class education to anyone anywhere.” Former hedge fund manager. Lessons from arithmetic to Calculus. Khan himself delivers lectures in an engaging style, with some kind of blackboard program. It’s a lot better than it sounds. You can either watch videos by themselves or go through a coaching section systematically, going from basic arithmetic all the way to calculus and differential equations.
If a collaborative model appeals to you, you’ll want to check out Wikiversity and its companion Wikibooks. Both of these projects are part of Wikimedia, which hosts Wikipedia. Of course, Wikipedia itself is a good source of information on math and science topics, but some of the articles are quite technical and challenging for people whose background in these subjects isn’t quite as strong as those of the authors. Wikiversity’s motto is to “set learning free” and intends to be a base for learning communities. Wikibooks is a project that intends to build collaboratively-edited textbooks the way that its sister site Wikipedia intends to build a community-authored encyclopedia. The downside is that the completeness and quality of the content varies widely as it does on Wikipedia. But the good stuff is really good. The most complete material tends to be in math and the hard sciences.
MIT was one of the first universities to put their content online. MIT OpenCourseWare was originally intended to help academics at other universities improve their own lessons by checking out lecture videos, lecture notes, and other materials. It was quickly adopted by independent learners and MIT eventually started to offer self-contained, free open courses. There are hundreds of course materials available online, ranging from notes to complete textbooks. And since this is MIT, the math and science content is very strong.
On BetterExplained, Kalid Azad offers clear, simple math lessons explaining everything from the meaning of the mysterious constant e to Bayesian probability. Azad believes in developing intuition even at the initial expense of rigor, which may ruffle a few mathematician’s feathers. But you’ll walk away with a new understanding of the world.
UC Berkeley Webcasts
Another major research university offering free content is UC Berkeley. You can watch video lectures on lots of concepts, but most of the lectures offered seem to be from the sciences. The lectures go back to 2001. If you regret not being able to actually get into Cal, this is the next best thing.