Carlos William Castillo-Garsow

Associate Professor
Eastern Washington University


Carlos William Castillo-Garsow was named for mathematician Carlos Castillo-Chavez and poet William Carlos Williams. He earned his B.S. in biometry and statistics from Cornell University in 2003, and a M.A. in linguistics from the State University of New York at Buffalo in 2006, before combining these disciplines to study mathematics education at Arizona State University, where he completed his Ph.D. in 2010. He completed a three-year post-doc at Kansas State University and is now newly promoted to Associate Professor in the Mathematics Department at Eastern Washington University. Castillo-Garsow received the 2017 College of STEM Chairs’ Excellence Award in Teaching and serves on the Editorial Board for the Journal of Mathematical Behavior.

Castillo-Garsow’s research focuses on the conceptual development of applied mathematics and the teaching and learning of mathematical modeling. He focuses on the developmental transition from students working on assigned problems to researchers who develop and investigate their own questions. Research projects have included how students’ conceptions of time influence their development and understanding of mathematical models and how successful faculty mentors guide undergraduate students in the development of a mathematical research question.

Castillo-Garsow has been a participant in the Mathematical and Theoretical Biology Institute (MTBI) since its founding in 1996. MTBI is a summer REU and pipeline program at Arizona State University that focuses on the recruitment and retention of minorities to the mathematical sciences. Castillo-Garsow has been mentoring research projects at the institute as an advanced student since 1997 and as faculty mentor since 2015.

At Eastern Washington University, Castillo-Garsow takes an innovative approach to course design, using student evaluations, scores in subsequent classes, certification exam scores, and personal interviews to evaluate every aspect of his courses. He continually makes revisions to his courses at all levels in order to fit the needs and interests of his students. Revisions vary from small changes to the way he communicates expectations on the first day of class to complete course rewrites to present information in a context that is personally significant to his students.

Castillo-Garsow also introduced a new course sequence for secondary math majors that focuses on developing future mathematics teachers as innovators who design lessons in response to the needs of their individual classes. He uses the results of his research to mentor future mathematics teachers in how to listen to the interests of their students, evaluate their mathematical understandings, and develop tailored lessons that serve their students.

For hobbies, Castillo-Garsow studies and teaches the global history of mathematics. He’s particularly interested in studying and reclaiming historical mathematics outside of the European tradition. He likes to see diverse students connect to the mathematical innovations of their own cultures and take pride in those mathematical accomplishments.

He also practices and presents indigenous Mexica dances with the Mihtotiliztli Spokane danza group.

“Hispanic Heritage is a mixed heritage. We come from a lot of places and we are a blend of a lot of cultures. But it’s also easy to focus narrowly on just one aspect of our culture: the people or neighborhood right in front of us. We have a great opportunity to learn from our many heritages and become the best of ourselves. We need diverse role models, who all embody different aspects of our culture and the many different ways that we can see ourselves as confident, successful, and Hispanic people.”