The words "Math Nerd" or "Math Geek" are omnipresent. So, what happens when you use such terms to promote a website?
One example is MathNerds.com is an interesting, refreshing twist to things. Basically, it is a "reverse" site, in that an international, volunteer network of mathematicians (i.e. the Math Nerds) provide free, "discovery-based, mathematical guidance."
The group refuses to supply answers to homework, tests, etc....but focuses on providing hints, suggestions, and resources designed to help the "student" both understand and solve their own mathematical problems. No pay or fee...just hopefully a "thank you" from the student.
When you visit the site, check out the links "Best,"...to see some of the best questions (and answers) presented on the site.
Also, the link "Texas" pays homage to the R.L. Moore teaching method developed at the University of Texas from 1920-1969. If you have never heard of this approach, it is worth a browse.
As second example, MathDork.com claims to use animation to enhance and motivate an "intuitive way" to learn Algebra I. Provided by Royanne Levy, a mathematics teacher/tutor, the site falls short of its name!
A third example is MathGeek.com, a blog site by Eric Hall (NOT his picture below)...oddly a patent attorney in Houston (TX) and former professor of electrical engineering at SMU. His blog has some interesting observations, but be sure to look at his dynamic sliderule simulation (awesome!) and his "Aphorisms." Better...but he seems to want to appear to be a Math Geek, but not really be one!