Linda Dacey, consultant and professor emeritus at Lesley University, has always believed that learning mathematics should be conceptually based and enjoyable. Her major interests are problem solving, number sense, and strategies for differentiation. Linda is the coauthor with Anne Collins of the Zeroing in on Number and Operations series, as well as other titles focused on teaching mathematics at the K-2 level.Karen Gartland is a mathematics coordinator and classroom teacher at Groton-Dunstable Middle School. She enjoys working with students of all ages with a focus on conceptual understanding of mathematics through critical thinking and application as well as best practices for integrating technology. Karen is also an adjunct faculty member at Lesley University. Jayne Bamford Lynch is a district math instructional coach in Cambridge, Massachusetts, where she spends most of her days in elementary classrooms supporting coaches, teachers, and students. Jayne presents workshops for teachers, administrators, and parents on a multitude of topics and is also a National Faculty member of the School of Education at Lesley University.