A proven method that makes homework time extra productive is the SQ3R which stands for survey, question, read, restate and review. Usually homework and tests cover the same topics. Doing homework is really a way of studying for a test.
Here's how it works:
Survey: Have your child quickly look over a reading assignment and notice what it's about. Some clues can be found in headings, pictures and bold type.
Question. Next they should think of questions about the material. It helps to turn headings into who, what, when, how and why questions.
Read. Now, it's time to read the assignment. Can your child find answers to the questions? Suggest that they take notes and highlight key sections as they read.
Restate. Your child can test themselves by repeating what they have learned in their own words. They should focus on the lesson's most important points.
Review. Glancing over the material again (both right away and days later) will make it easier to remember. Your child might also study questions, if the book provides them.
Information taken from Homework & Study Skills 2011 The Parent Institute