Why use free math worksheets? Easy. These worksheets can save you a lot of time and money and when you're a busy homeschool mom teaching several children, this means a lot.
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.
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.
From a teacher's perspective our competition is tough. Passing out a handout of 30 problems that are all in a format of 534x25= is not as stimulating in the students' eyes as playing games such as Grand Theft Auto and Resident Evil.