http://www.mindwareonline.com/MWESTORE/Home/HomePage.aspx

Developing Math Talent.
Assouline, S. & Lupkowski-Shoplik, A.
ISBN: 1882664922

The mindware math books have been great for my DS. They are for adding to a learning program with more logic and different thinking than you find in most courses. They have some sample pages to print out to try.

You may also want to check out Developing Math Talent for a list of topics not usually in regular Math programs.

Many here are using EPGY for Math. You may want to look at the threads on this. There is a group rate. If I remember correctly it's $135 a year. I'm not sure if there is a placement test.

I've heard Alex has tests for placement.

I've also saw Grade level Testing books at our library.

Somewhere I saw a list of suggested Math Programs for Gifted Math Students. It may be in either Developing Math Talent or A Nation Decieved. If I find this I'll get back to you.