In other words, they never memorized their multiplication tables! Many times I have seen a student do poorly due to a weakness in basic math facts they should have learned in third grade.
Therefore creativity is a must for worksheets to be successful : Regardless if you are trying to review math, science, reading, writing, health, or social studies, your goal should always be to try and create something that will generate desire in the students to actually want to do it. If you can do this, the battle is practically over already.
I recommend getting one of these books when you first begin homeschooling and use it as a reference throughout your homeschool journey. Regardless of how long you homeschool, you'll always have doubts and questions about how your child is performing.A scope and sequence book can put your mind at ease.
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.