Remember to select worksheets that are the right level difficulty for your child. Get something too hard, and your child will become discouraged. Make it too easy, and they won't learn much.
Point is, whatever it takes to get students actively involved with the reviewing process where they are not bored and effectively reviewing grade level material in order to prepare them for state or quarterly assessments.
Great, fun and free math worksheets should be able to present a mathematical problem in different ways. Math is after all nothing more than a numeric expression of some of life's simplest questions:
Review subtraction of 2 numbers whose sums would be 18 or less