That's how i do it, but it's not just that, you need to be able to apply it and know how to answer the Qs. Like for certain papers, they're looking for an answer, for example in my RE exam, i had to answer a part D question where the question stated something like "Jesus was a bad teacher, do you agree or disagree?" i could have states a thousand perfectly fine reasons of why i disagreed or agreed but would have got it wrong, i had to organize the question with one point of view, the other and then my personal opinion also stating why i understand the other point of view.
so it's a lot more difficult than that, and for Maths especially because for that you need to know how everything works and how to apply it.