How to read a math or physics section in twenty minutes

Textbooks are not novels. Read them out of order, with a pencil, and stop when you have what you need.

A section of Active Calculus or OpenStax Physics is about ten pages. Read straight through and you will spend an hour and remember the pictures. Read it like this and you will spend twenty minutes and remember the ideas.

1. Summary first. Read the section summary or the Mathub notes page (big ideas, formulas, pitfalls) before the text. Now you know what matters and the text becomes confirmation.
2. Definitions and boxed results. Copy each one in your own words on one line. If you cannot, that is the sentence to reread.
3. One worked example, actively. Cover the solution, try the example, uncover line by line. Do this for one example per new idea, not all of them.
4. Skip the proofs the first time unless the exam covers them. Come back after the practice questions if you are curious.
5. Five questions. Immediately do five practice questions on the section. Reading without questions is the most common wasted hour in college.

Mark it up

• Question marks in the margin at anything unclear; bring those to office hours or the discussion board.
• A star next to any formula the notes call "key". That is your formula-sheet list.
• Write the units of every physics quantity in the margin the first time it appears.