Kahn Academy

While googling “permutations” I happened upon a Khan Academy tutorial (PRECALCULUS > PROBABILITY AND COMBINATORICS). A guy named Sal explaining the permutation formula and how to use it. I have not given this topic a thought since high school and while familiar with Kahn Academy, I never watched one of their tutorials. Wow. This seems like a great way to learn. Math was really hard for me but if I had had access to these I think I would have done much better.