### About the Authors

These modules are based on materials developed by the authors and used in extended professional development activities with over 1000 practicing K-8 teachers during the past ten years in 38 institutes of the Leadership Program in Discrete Mathematics (LP-DM). The first 25 institutes of the LP-DM were funded by the National Science Foundation during 1995-2001, during which time these materials were developed.

Joseph G. Rosenstein served as Director of the LP-DM and Valerie A. DeBellis was Associate Director of the LP-DM. They are uniquely qualified to write these materials because no other program has introduced discrete mathematics systematically to K-8 teachers.

The LP-DM was co-sponsored by DIMACS, the Center for Discrete Mathematics and Theoretical Computer Science, based at Rutgers University, and by the Rutgers Center for Mathematics, Science, and Computer Education.

Joseph G. Rosenstein is a professor of mathematics at Rutgers, the State University of New Jersey and was founding director of MetroMath: The Center for Mathematics in America's Cities, an NSF-funded Center for Learning and Teaching.

Valerie A. DeBellis is a mathematics educator and a visiting scientist at The Shodor Education Foundation in Durham, North Carolina. She has taught discrete mathematics to prospective and practicing K-12 teachers for the past fifteen years.