Math professor Harold Reiter has some essays on "Exploring Fundamental Concepts In Elementary Mathematics" at http://www.math.uncc.edu/~hbreiter/Zoom/ConceptsIndex.htm . "The essays are based on the idea that mathematics should can be developed well when students are motivated by rich exploratory problems that are easy to understand but require the development of mathematical structure to solve."

He teaches at Math Zoom http://www.mathzoom.org/summer-camps/summer-camp/faculty , a camp for gifted math students, and has written problems for MathCounts. He lists many math resources at his site http://www.math.uncc.edu/~hbreiter/ .

He has pretty impressive credentials and it's clear he inspired someone in his life to rock at math. His daughter placed 3rd at national Mathcounts, won Westinghouse, was on the national Chem olympiad team, and has a PhD in math. She teaches for AoPS and there are articles about her on the website. Given his work with teachers and students in math circles, it's clear he has inspired many other students and served as a mentor to mathy kids for a very long time.

His website is amazing with tons of resources.

Ooh, some great stuff there - thanks for posting, Bostonian!

Professor Reiter will be teaching at epsilon camp in Colorado this summer.

http://epsiloncamp.org/epsilon_day.php