Save Time : Free worksheets not only save you money, they can also save you time. If you decide that it is best for your child to do worksheets especially tailored for his needs, by doing a little research for printable math worksheets found online, you don't have to make the worksheets yourself. This can save a lot of time. Worksheets aren't that difficult to make, but it can be time consuming.
For example, since I want to make sure my students get accustomed to reviewing the various math concepts and standards we've learned all year, I have them practice regularly. I want them to get to a point where they are so familiar with grade level math content, that solving these types of problems becomes automatic.
When you're teaching your student to write, there are a whole host of worksheets online that you can use. Many of these include clipart that will help the students learn the sounds of letters and letter combinations. There are other sheets that help the student learn to write his or her numbers. It's helpful having printable worksheets for something like this, because parents often go through quite a few of these before the child masters writing the numbers or letters correctly.
However for the most part, when a worksheet is needed to help drill down a procedure, standard, or lesson, its effectiveness can and will vary.