Writers of math texts believe that extra words and repeats get in the way of clarity. Never start in the middle of the book, the chapter, or the page. Each page assumes you have mastered the previous pages. Understand each sentence before you go on. Reread as many times as necessary for you to master an idea.
Mastery can take minutes, hours or days.
Do not skim diagrams and other kinds of illustrative material. Words and symbols of math have very specific meanings. If you are at all uncertain about the meaning of a term, look it up or ask someone to explain it. Write as you read. A. Work out proofs, derivations, and sample problems.