That might not work because IEP’s are documents that are mandated by the federal government to help with the educational needs of children with disablities, not ones who are gifted. Your idea of asking for testing is a good one, but I can guarentee the school district will probably drag it’s feet at accommodating the parent in this request.
Looks like there's lots of good advice on the thread already...
If you want to keep your daughter in the public schools, an IEP is an option. I had one for most of my time in school (graduated 2003). You might have to push for it if they don't have a gifted program.
Push to get her out of that math class if she's ready for something more advanced. There are few things worse than being stuck in class where either 1) the work is far too easy and there is no challenge or 2) the teacher uses her to teach the other kids. The latter seems to be one of the approaches that the NCLB proponents like to use... it caters to the lowest common denominator. My sister just graduated with a teaching degree, and I've been trying to explain to her the flaws of that approach, and she just doesn't get it. Don't be surprised to find similar attitudes with your daughter's teachers.