My son likes doing math and his school has used prodigy for several years. A couple different schools through the last couple years, but they both have used prodigy. The school has provided the basics for him, but we finally went ahead and got him the parent upgrade that includes some additional content.
Prodigy is free to schools and students – completely funded by the extras parents can add. So far my son is still loving it. He’s about maxed out the grade level content available to him – It includes K-8, so I’m looking at getting him excited about Kahn academy after he has completed everything there is to do in Prodigy. Most kids that play with Prodigy won’t reach that max until they are close to the end of 8th grade.
I can highly recommend Prodigy though. My son finds it challenging and interesting as well as having a fun component!

I am a SAHM/WAHM of three boys ranging in age from 16 to 32. We are working on saving enough for college at the same time as dealing with school and our older independent kids. I author a few blogs, including http://teched4kids.com. I have in the past taught computer information technology classes for the local university and taught workshops for kid's in technology education besides being the Kentucky State FIRST LEGO League Championship Coordinator from 2005 to 2008. I now work as a computer consultant, run a handmade home business, and am available for workshops. Life here is always an adventure!