It's been a while since I took it, but I think I spent an hour or two a week watching the videos and reading notes and whatever, and then maybe another 3-5 hours on the programming assignment. It was probably less than that on the earlier programming assignments, and more on the later ones as things got more complicated later on. And I might have spent more time on the videos on certain sections, because of re-watching sections that weren't intuitively clear to me right away. In particular, some of the math'ier stuff where he explained the stuff about using partial derivatives to calculate the error gradients for neural networks... that stuff I had to put more work into since my math background isn't real strong (I never took multi-variable calculus).
All of that said, you can get through the class and learn and understand the material at the level he teaches it, even without completely understanding partial derivatives (a point he makes in the lecture). But having a strong calculus background certainly wouldn't hurt.
All of that said, you can get through the class and learn and understand the material at the level he teaches it, even without completely understanding partial derivatives (a point he makes in the lecture). But having a strong calculus background certainly wouldn't hurt.