Tests can be very useful. You could find things to tweak in your homeschool. Or, with a good placement test, you could find which Math program would the best fit for your child. If you're not sure what your student's reading level is, check out the Quick Reading Assessment.
I'm currently working to make the Reading Assessment easier to use. While I'm fiddling with it, check out the placement tests available to you.
Filmmaker, Writer, Empty Nester
P.S. Want to learn more about standardized tests and homeschooling? Watch the To Test or Not to Test? webinar.