Brightstorm has over 2,500 free math videos from Pre-Algebra through Calculus that offer actual teachers explaining and demonstrating math concepts. What is unique about Brightstorm is that with each concept, a set of 2-3 problems that demonstrates the concept is included.
Why UDL? This type of online tool offers multiple means of representation and engagement of math concepts that students often miss. Having the problems explained furthers the understanding for many students who need to see and hear several examples.