Olaf College, where he serves as the Director of Mathematics Education. After three years of teaching mathematics at Brookline High School, he got a Ph.D. in Number Theory from Boston University. He was co-director of research on the Math Science Partnership Focus on Mathematics. As North American Director of Budapest Semesters in Mathematics Education, he leads a study abroad program for pre-service and in-service teachers. He served as Principal Investigator for Assessing Secondary Teachers’ Algebraic Habits of Mind, an NSF DRK-12 collaborative grant with colleagues from Boston University and Education Development Center, Inc.