Here are some websites for your child to try to practice subtraction facts.
Math Baseball http://www.funbrain.com/math/
Math Magician http://www.oswego.org/ocsd-web/games/Mathmagician/cathymath.html
Subtraction Machine http://www.amblesideprimary.com/ambleweb/mentalmaths/subtractiontest.html
Here is the link to the Michigan website: http://www.michigan.gov/mde/0,1607,7-140-22709_31168_31355-95471–,00.html
Just click on Grade 3 Mathematics. (The ELA isn’t really usable because the reading selections aren’t shown.)
I can’t believe that we have less than two weeks until school begins. Hopefully the pipe and heating work will be completed soon, and I’ll be able to get into my classroom to get things set up for the first day. Right now, things are a bit of a mess!
For kids who want to test their knowledge of continents and oceans, there’s a great quiz site here: http://www.sheppardsoftware.com/World_Continents.htm
There are other quizzes and activities to try, too, in other subject areas. Here’s the link for the general page:
http://www.sheppardsoftware.com/
Parents may find themselves addicted to the quizzes (especially the US state geography one!) I like States 3. My average error was 17 miles. 
Here’s another math link. The kids are loving this page, but please make sure they are practicing facts with x3, x4, x6-9, etc., not just x0. Thanks!
I found a website aligned with Everyday Math 3rd grade goals. There let the kids practice what they are learning in class. It’s at http://www.kent.k12.wa.us/ksd/ms/math/math3.htm.
