As a pretty average student in my school lie, I have had been troubled by this particular subject.
Before you sit down to solve the various questions from the back of the book or from other sources, make sure that you have read all the important points of the chapter(s) really well.
If not, you can always turn the pages back again and then proceed with answering the questions.
This phrase is soon going to become void and will never be used ever again if you follow my steps as said above.
Homework, projects, assignments, do it all with a snap of your fingers.