The IM Story

Bill McCallum has dedicated his life to helping teachers, educators, mathematicians, and policymakers show fidelity to both mathematical coherence and student learning.

He is an Emeritus Distinguished Professor of Mathematics at The University of Arizona, where he researches number theory and arithmetical algebraic geometry, authors textbooks, and advises researchers and policymakers. Bill’s work as a lead writer of the Common Core State Standards in Mathematics earned him the Award for Distinguished Public Service from the American Mathematical Society and the Dolciani Award from the Mathematical Association of America.

As CEO and cofounder of Illustrative Mathematics, Bill chairs the organization’s board of directors, helping craft IM’s strategic direction and contributing to the curricula. He also represents IM to funders, at speaking events, and in workshops.

LaToya Byrd is an accomplished educator with a passion for mathematics education and a commitment to equity and access for all students. LaToya has dedicated her career to supporting educators and improving student outcomes. She holds a BS in Education, an MEd, and an EdD, all from Georgia State University.

Throughout her career, LaToya has been involved in state-level education initiatives, working with the Georgia Department of Education to review state standards, test development, and data review. She has also presented at local, state, and national conferences. Her expertise in mathematics education and commitment to equity have made her a valued voice in education policy discussions.

As the vice president of client success for IM, LaToya leads the team that supports classroom implementation of IM K-12 Math through professional learning for IM teachers, coaches, and school leaders, and through supporting educators who are using other products and services that serve the IM Classroom.

Ebony Jones brings over 20 years of experience in human resources, with a passion for fostering inspiring workplaces that prioritize employees. Recognizing the pivotal role employees play in organizational success, she led the initiative to rename IM’s Human Resources department to Employee Success in 2025, underscoring her commitment to people-first strategies.

Promoted to Vice President of Employee Success at IM, Ebony draws on a rich history of leadership in both nonprofit and for-profit sectors. Her career spans senior roles in children’s behavioral health, therapeutic residential care, and private day school education, where she consistently championed advocacy for children and families. In 2020, she was appointed as a Special Education Advisory Committee Member (SEAC) for Chesterfield County Public Schools in Virginia, reflecting her dedication to supporting equitable education.

In her role at IM, Ebony oversees employee relations, performance management, talent acquisition, diversity, equity, inclusion, and belonging (DEIB) programming, internal communications, and employee success operations. She is deeply aligned with IM’s values of diversity, courage, and collaboration, ensuring these principles are embedded in every aspect of the organization.

Sara Allan is the director of Early Learning and Education Pathways at the Bill & Melinda Gates Foundation. She joined the foundation in 2011 as the deputy director of the K-12 team. Sara most recently led the foundation’s work to expand research and development of promising solutions to longstanding teaching and learning challenges that keep students from reaching their full potential. Sara currently directs two program strategies: One focuses on improving outcomes for children in early learning programs, ensuring they enter kindergarten ready to learn. The other helps young people successfully navigate a path from high school through post-secondary, developing agency, skills, and social capital while attaining credentials that enable upward mobility in the workforce.

Previously, Sara was a district-level leader at Portland Public Schools, where she led reform initiatives, which included the school performance management, restructuring the portfolio of schools, redesign of core human resource processes and systems, and directing research, evaluation, data policy, and analysis. Before working in education, Sara was a strategy consultant with the Boston Consulting Group, working with private and public sector clients on issues of strategy, organizational development, and growth in North and South America. She serves as a board member and advisor to for-profit and nonprofit organizations and was recipient of the Broad Residency in Urban Education and a Presidential Leadership Scholar.

A dual citizen, Sara grew up in a family of educators and attended Canadian public schools from kindergarten through graduate school. She holds a BS in Mathematics and Economics (summa cum laude) from the University of Toronto and an MBA from the Richard Ivey School of Business at Western University.

Barbara Chow serves as the education program director at the Heising-Simons Foundation.

Her early years of service were spent working for the Senate Democratic Policy Committee and the Senate Budget Committee, followed by the Clinton Administration, where she was deputy director of the Domestic Policy Council; associate director for education, income maintenance, and labor programs at the Office of Management and Budget; and special assistant to the president for White House Legislative Affairs.

Barbara went on to serve as the House Budget Committee policy director and the executive director of the National Geographic Education Foundation. She also spent eight years as the education program director for the William and Flora Hewlett Foundation.

Barbara holds an MA in Public Policy from the University of California, Berkeley, and a BA in Government from Pomona College. In addition to serving on the board of Illustrative Mathematics, Chow is also on the boards of the Learning Policy Institute, the National Public Education Support Fund, and PBLWorks.

Heather Hill studies policies and programs designed to improve mathematics teacher and teaching quality at the Harvard Graduate School of Education.

Her recent research focuses on teacher professional development, instructional coaching, teacher evaluation, changes over time in teachers’ mathematical knowledge and instructional quality in mathematics, and teacher experiences and characteristics that lead to high-quality instruction and stronger student outcomes.

Heather and her team have developed assessments that capture teachers’ mathematical knowledge for teaching and teachers’ mathematical quality of instruction, assessments now widely available to researchers, instructional coaches, evaluators, and policymakers via online training and administrative systems.

Heather is a fellow of the American Educational Research Association (AERA) and serves on the AERA grants board. She also serves on the editorial boards of several journals, and as an advisor to numerous research projects and policy efforts in the US and abroad. She is coauthor of Learning Policy: When State Education Reform Works with David K. Cohen (Yale University Press, 2001).

Heather holds a PhD from the University of Michigan and a BA from Swarthmore College.

Kristin Umland believes that by coordinating the expertise of teachers, mathematicians, mathematics educators, and business professionals, we can help all students realize their mathematical potential.

Before joining the IM team, she was an associate professor in the Department of Mathematics and Statistics at the University of New Mexico (UNM). After joining UNM with a PhD in Mathematics, she carried out research in mathematics education, taught pre-service and in-service elementary and secondary teachers, and conducted education outreach at the local, state, and national levels. A recipient of both the Louise Hay Award and the AMS Impact Award, Kristin’s goal has always been to improve the mathematical and pedagogical quality of children’s learning experiences.

Kristin is cofounder and president of IM.

George Zettler is a mathematician and financial manager. He is a cofounder and managing member of Flowing Shape Advisers, LLC, a consulting group specializing in mathematical analysis.

Prior to Flowing Shape, Zettler cofounded Ellington Management Group LLC and held a position at Kidder Peabody.
George also served as a professor of mathematics at Columbia University for nine years, where he conducted original research in representation theory and algebraic geometry.

He holds a PhD and an AB in Mathematics from the University of Maryland and Harvard University.