I am not sure about reading, but writing is impossible for me, in dreams. When I write something, and I read it again, I see that I actually wrote something else. So I try to correct it, and again it is wrong; and that is very frustrating. Doing calculations, even as simple as counting my fingers, is also impossible.

From what I read online on topic of lucid dreaming, different people have different "abilities" and "disabilities" in dreams, but some of them are rather common (for example the inability to count one's fingers). If you make a habit of testing these skills a few times a day, it may help you notice when you are dreaming.