I think you just need to start asking, "Why?" Whether you ask yourself or the teacher, doesn't matter. But I'd start by asking yourself first, then the teacher if you can't figure it out.
Try to figure out how the math works, not just how to do it. You can make notes of what you find, but I think you'll discover when you try to figure out how math works, not just how to do math, you won't need notes as much.
Hope this helps. If not, I don't really know how to help you. I've always been better at figuring math out, rather than just memorizing it.