Be it Mathematics, Science or English if you don't comprehend what you're reading, you might as well play game. One of the most difficult ordeals a student faces is reading and understanding a textbook.
When reading your school books, begin by skimming over the materials to be covered by the lesson. Then read the introduction and summary where the important points are noted. Next, watch out for the major points - those items printed in bold, italics, charts, diagrams and others.
Every end of each paragraph, ask yourself if you have learned any or none at all. Try also to relate it with what you already know or what was recently discussed in class. In his book How to Study Effectively, Dr. Chris Parsons stated that keeping up with your work will not benefit you grade-wise, but it will also teach you to handle responsibility and prepares you for another semester and the world ahead.
Jotting down notes does not mean you record everything the teacher says. The good notes only keep important points and skip nonsense or irrelevant. Keep special attention on things you find interesting and your teacher has stressed out. If you do not understand something about what the teacher have discussed and realized it only at home, do not hesitate to approach your teacher about it the following day.