Building Elementary Math Skills... Online Practice Exercises

I was Stumbling this morning and found a cool math practice site for children Pre-K through 5th grade called IXL.com. They offer a wide range of brain building exercises to strengthen you student's math skills and build confidence in your young student.

IXL.com offers both a free version and paid version. I signed in as a guest and did a bit of playing myself... just to see if this was something we might use over the Summer months to challenge our children and keep their minds from going soft. I think the paid membership of just $9.95 a month or $79 for a year is a reasonable price, given you'll have full access to the site's 100+ math building skills and all the practice you can possibly ask for!

The coolest part, from a homeschooler's perspective, is this site actually tracks your children's scores for you... additionally the questions grow increasingly challenging as they improve.

Does anyone out there have any personal experience with this site? I'd love to hear from you if you do!