Don S. Balka, Ph.D., is a noted mathematics educator who has presented more than 2,000 workshops on the use of math manipulatives with PK-12 students at national and regional conferences of the National Council of Teachers of Mathematics and at in-service trainings in school districts throughout the United States and the world.

He is Professor Emeritus in the Mathematics Department at Saint Mary’s College, Notre Dame, Indiana. He is the author or co-author of numerous books for K-12 teachers, including Developing Algebraic Thinking with Number Tiles, Hands-On Math and Literature with Math Start, Exploring Geometry with Geofix, Working with Algebra Tiles, and Mathematics with Unifix Cubes. Balka is also a co-author on the Macmillan K-5 series, Math Connects and co-author with Ted Hull and Ruth Harbin Miles on four books published by Corwin Press.

He has served as a director of the National Council of Teachers of Mathematics and the National Council of Supervisors of Mathematics. In addition, he is president of TODOS: Mathematics for All and president of the School Science and Mathematics Association.

Ted H. Hull completed 32 years of service in public education before retiring and opening Hull Educational Consulting. He served as a mathematics teacher, K-12 mathematics coordinator, middle school principal, director of curriculum and instruction, and a project director for the Charles A. Dana Center at the University of Texas in Austin. While at the University of Texas, 2001 to 2005, he directed the research project “Transforming Schools: Moving from Low-Achieving to High Performing Learning Communities.” As part of the project, Hull worked directly with district leaders, school administrators, and teachers in Arkansas, Oklahoma, Louisiana, and Texas to develop instructional leadership skills and implement effective mathematics instruction. Hull is a regular presenter at local, state, and national meetings. He has written numerous articles for the NCSM Newsletter, including "Understanding the Six Steps of Implementation: Engagement by an Internal or External Facilitator" (2005) and "Leadership Equity: Moving Professional Development into the Classroom" (2005), as well as "Manager to Instructional Leader" (2007) for the NCSM Journal of Mathematics Education Leadership. He has been published in the Texas Mathematics Teacher (2006), Teacher Input Into Classroom Visits: Customized Classroom Visit Form. Hull was also a contributing author for publications from the Charles A. Dana Center: Mathematics Standards in the Classroom: Resources for Grades 6–8 (2002) and Middle School Mathematics Assessments: Proportional Reasoning (2004). He is an active member of Texas Association of Supervisors of Mathematics (TASM) and served on the NCSM Board of Directors as regional director for Southern 2.

Ruth Harbin Miles coaches rural, suburban, and inner-city school mathematics teachers. Her professional experiences include coordinating the K-12 Mathematics Teaching and Learning Program for the Olathe, Kansas, Public Schools for more than 25 years; teaching mathematics methods courses at Virginia’s Mary Baldwin College; and serving on the Board of Directors for the National Council of Teachers of Mathematics, the National Council of Supervisors of Mathematic, and both the Virginia Council of Teachers of Mathematics and the Kansas Association of Teachers of Mathematics. Ruth is a co-author of five Corwin books including A Guide to Mathematics Coaching, A Guide to Mathematics Leadership, Visible Thinking in the K-8 Mathematics Classroom, The Common Core Mathematics Standards, and Realizing Rigor in the Mathematics Classroom. As co-owner of Happy Mountain Learning, Ruth specializes in developing teachers’ content knowledge and strategies for engaging students to achieve high standards in mathematics.