Mark earned his Ph.D. in Education from the University of North Carolina Chapel Hill in 2005. He taught mathematics in grades 6-12 in northern California public schools, becoming a National Board Certified Teacher in Early Adolescence Mathematics in 1999 (renewed in 2009). Mark's professional work focuses on supporting pre-service and experienced teachers in creating opportunities for all students-particularly those from groups historically underserved by traditional practices of schooling-to learn important mathematics concepts and skills. He is co-PI of the NSF-funded Fullerton Master Teacher and Mathematics Teacher Fellows project that aims to impact mathematics teaching in two high-need school districts. He served on the NCTM Board of Directors from 2011-2014.