Courtney Koestler

As a proud former public school teacher and instructional coach, Dr. Courtney Koestler has taught and engaged in teacher-research in culturally, linguistically, and economically diverse communities in urban, suburban, and rural schools. Recognized and awarded for teaching, research, and outreach, Dr. Koestler is committed to examining and addressing inequity and injustice in all areas of scholarship.

Peer-Reviewed Journal Articles

Koestler, C., & Thanheiser, E. (In Press) Teaching Mathematics Through a Critical Literacy Lens.

Thanheiser, E., Robinson, M., Han, S., Sugimoto, A., Koestler, C. & Felton-Koestler, M. (2025). Belonging in the math classroom: Data reasoning about ourselves and others. Mathematics Teacher: Learning and Teaching PK–12, 118(10), 750-759.

Sugimoto, A., Han, S., Koestler, C., Thanheiser, E., Felton-Koestler, M., & Robinson, M.. (2025). Dilemmas encountered while planning social and/or political elementary mathematics tasks. School Science and Mathematics. Advance online publication.

Koestler, C. (2025). Agency and critical literacy in elementary mathematics. Mathematics Teacher: Learning and Teaching PK–12, 118(8), 601–609.

Koestler, C., Wolfe, A., Peasley, T. M., Lisy, J., & Weiss, C. (2024). Teaching on days after: A case clinic approach to understanding more humanizing pedagogies in early childhood-elementary teaching education. The Journal for Research and Practice in College Teaching, 9(2).

Thanheiser, E., Koestler, C., Sugimoto, A. T., & Felton-Koestler, M. D. (2023). Construct it! What’s in a name? Collecting, organizing, and representing data. Mathematics Teacher: Learning and Teaching PK–12, 116(10), 746–752.

Hallman-Thrasher, A., Lui, C., Koestler, C., Strachota, S., & Thompson, J. (2022). Designing and implementing a STEM summer camp. Technology and Engineering Teacher, 81(4) 20–25.

Thanheiser, E., & Koestler, C. (2021). If the world were a village: Learning mathematics while learning about the world. Mathematics Teacher Educator, 9(3), 202–228.

Bartell, T., Koestler, C., & Foote, M. Q. (2021). Mathematics teachers’ understanding of privilege and oppression. Mathematics Teacher Educator, 9(3), 168–183.

Hallman-Thrasher, A., Koestler, C., Dani, D., Kolbe, A., & Lyday, K. (2018). Graphing stories for a three-act task. Mathematics Teaching in the Middle School, 24(2), 90–96.

Felton-Koestler, M. D., & Koestler, C. (2017). Should mathematics teacher education be politically neutral? Mathematics Teacher Educator, 6(1), 67–72.

Felton, M. D., & Koestler, C. (2015). “Math is all around us and...we can use it to help us": Teacher agency in mathematics education through critical reflection. The New Educator. 1(4), 260–276.

International, Peer-Reviewed Conference Proceedings 

Koestler, C., Felton-Koestler, M., Thanheiser, E., & Sugimoto, A. (in press). Core practices central to connecting mathematics to social and political issues when designing and implementing tasks in elementary classrooms. Proceedings of the 15th quadrennial meeting of the International Congress on Mathematical Education. Sydney, Australia. 

Thanheiser, E., Rubel, L., Herbel-Eisenmann, B., & Koestler, C. (2025). Recontextualizing engagement with data visualizations in the context of the social and ecological. Le Roux, K., Coles, A., Solares-Rojas, A., Bose, A., Vistro-Yu, C., Valero, P., et al. (Eds.), Proceedings of the 27th ICMI Study Conference (Mathematics Education and the Socio-Ecological) (pp. 378–385). ICMI and MATHTED.  

Thanheiser, E., Robinson, M., Sugimoto, A., Han, S., Koestler, C., & Felton-Koestler, M., (2024). Creating a sense of belonging: Responding to (some of) Paola Valero’s 2023 PME plenary. (pp. 145–152). Evans, T., Marmur, O., Hunter, J., Leach, G., & Jhagroo, J. (Eds.) (2024). Proceedings of the 47th Conference of the International Group for the Psychology of Mathematics Education (Vol. 4). Auckland, New Zealand: PME.

Robinson, M., Thanheiser, E., Sugimoto, A., Penner, D., Han, S. B., Koestler, C., Felton-Koestler, M. D., Bartels, H. E., Thompson, J. A., & Wolfe, L. (2022). Building community in a research project team through identity sharing.  In A. E. Lischka., E. B. Dyer, E. S. Jones, J. Lovett, J. Strayer, & S. Drown (Eds) Proceedings of the 44th annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (pp. 479–487). Middle Tennessee State University.

Han, S. B., Thanheiser, E., Sugimoto, A., Robinson, M., Koestler, C., Felton-Koestler, M. D., Thompson, J. A., Bartels, H. E., & Wolfe, L. (2022). Connecting mathematics to the real world: One group of elementary mathematics teachers’ experience. In A. E. Lischka., E. B. Dyer, E. S. Jones, J. Lovett, J. Strayer, & S. Drown (Eds) Proceedings of the 44th annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (pp. 1395–1399). Middle Tennessee State University.

Scroggins, A., Hand, V., Bartell, T., Byun, S., Herbel-Eisenmann, B., & Koestler, C. (2018). Missing the brilliance of scholars of color: Mathematics teacher educator discourse in a white zone of proximal development. 13th International Conference of the Learning Sciences (ICLS) (pp. 1141–1144). London, UK: International Society of the Learning Sciences.

Larnell, G. V., LópezLeiva, C. A., Scroggins, A. D., Amidon, J., Foote, M. Q., Hand, V. M., Herbel-Eisenmann, B., Koestler, C., & Wager, A. A. (2016). Challenging the reframing of equity in mathematical systems: access, agency, and allies. In M. B. Wood, E. E. Turner, M. Civil, & J. A. Eli (Eds.), Proceedings of the 38th annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (pp. 1608–1611). The University of Arizona.

Books

Koestler, C., & Thanheiser. E. (Eds.). (2025) Building community to center equity and justice in mathematics teacher education: Volume VI Association of Mathematics Teacher Educators professional book series. Emerald Publishing.

Felton-Koestler, M., & Koestler, C. (2023). Data in your world: Understanding finances. Rourke Educational Media.

Koestler, C., Ward, J., Zavala, M. d. R., & Bartell, T. (2023). Early childhood mathematics lessons to explore, understand, and respond to social injustice. Corwin Press/National Council of Teachers of Mathematics.

Koestler, C., & Felton-Koestler, M. (2022). Data in your world: Exploring our schools. Rourke Educational Media.

Felton-Koestler, M., & Koestler, C. (2022). Data in your world: Communities near and far. Rourke Educational Media.

Koestler, C., Felton, M. D., Bieda, K., & Otten, S. (2013). Connecting the NCTM Process Standards and the Common Core State Standards for Mathematics Practices to improve instruction. National Council of Teachers of Mathematics.

Book Chapters 

Feeney, D. M., & Koestler, C. (in press). Rethinking neutrality in teaching and learning: Using a critical literacy approach in higher education. In Y. Sinha,  U. Miller, and M. Sinha’s (Eds.) A call to reason: Building inclusive pedagogy and wellness rhetoric into classrooms. Cognella Academic.

Thanheiser, E., & Koestler, C. (2025). Building community to center equity and justice in mathematics teacher education: An introduction. In C. Koestler & E. Thanheiser’s (Eds.) Building community to center equity and justice in mathematics teacher education (pp. 1–13). Association of Mathematics Teacher Educators professional book series. Emerald Publishing.

Robinson, M., Thanheiser, E., Koestler, C., Sugimoto, A., Han, S.B., Felton-Koestler, M., Thompson, J., Wolfe, L., & Bartels, H. (2025). Building critical community through identity sharing. In Koestler & Thanheiser’s (Eds). Building community to center equity and justice in mathematics teacher education (pp. 447–467). Association of Mathematics Teacher Educators professional book series. Emerald Publishing.

Thompson, J, Hallman-Thrasher, A., Heacock, K., Chen, L., & Koestler, C. (2025). Collaborative teams support teacher candidates in fostering students’ generalizations: Connecting representations within pattern tasks. In D. Polly & C. Martin (Eds.), Elevating clinical practice in mathematics education: Cases that showcase teaching practices in action (pp. 199–210). Emerald Publishing.

Zavala, M., Ward, J, Koestler, C., & Bartell, T. (2024). Building on students’ agency, empathy, and mathematics ingenuity. In A. Friesen, M. Mitsch, & K. Du’s (Eds). Advancing Equity and Inclusion in Early Childhood Education (pp. 196–218). IGI.

Koestler, C., Thanheiser, E., Kalinec-Craig, C,., Yeh, C., Jessup, N., & Wager, A. (2024). Justice-oriented mathematics education: A conversation among early childhood and elementary mathematics teacher educators. In B. Benken’s (Ed.) Reflection on Past, Present and Future: Paving the Way for the Future of Mathematics Teacher Education (pp. 29–43). IAP.

Koestler, C., Newton, J., & McGarry, J. (2023). Challenging ableist assumptions in mathematics problems. In T. Bartell, C. Yeh, M. Felton-Koestler, & R. Q. Berry III’s Upper elementary mathematics lessons to explore, understand, and respond to social injustice (pp. 124–132). Corwin Press/National Council of Teachers of Mathematics.

Guzman, L., Craig, J., Thanheiser, E., Raygoza, M. C., & Koestler, C. (2023). Upper elementary mathematics to explore people represented in our world and community.  In T. Bartell, C. Yeh, M. Felton-Koestler, & R. Q. Berry III’s Upper elementary mathematics lessons to explore, understand, and respond to social injustice (pp. 204–215). Corwin Press/National Council of Teachers of Mathematics.

Felton-Koestler, M., & Koestler, C. (2023). 3D modeling for water lesson. In B. Conway IV., L. Id-Deen, M. C. Raygoza, A. Ruiz, J. W. Staley, & E. Thanheiser’s Middle school lessons to explore, understand, and respond to social injustice (pp. 254–262). Corwin Press/National Council of Teachers of Mathematics.

Raygoza, M. C., Thanheiser, E., Koestler, C., Craig, J., & Guzman, L. (2023). Middle school mathematics to explore people represented in our world and community. In B. Conway IV., L. Id-Deen, M. C. Raygoza, A. Ruiz, J. W. Staley, and E. Thanheiser’s, Middle School lessons to explore, understand, and respond to social injustice (pp. 115–123). Corwin Press/National Council of Teachers of Mathematics.

Helfrich, S., Hartman, S.L., Dani, D., Felton-Koestler, M., Harrison, L., Koestler, C., Gut, D., Keifer Kennedy, M., Hicks, S., & Middleton, R. (2023). A reimagined research-based clinical model of educator preparation. In S.R. Helfrich and S.L. Hartman (Eds.), Exemplary Clinical Models of Teacher Preparation (pp. 29–60). Information Age Publishing.

Hand, V., Herbel-Eisenmann, B., Byun, S., Koestler, C. & Bartell, T. (2021). Tensions and failures in an analysis of whiteness among a racially and socially diverse group of mathematics teacher educators. In Andersson, A. & Barwell, R. (Eds.) Applying critical mathematics education (pp. 123–143). Brill.

Koestler, C. (2016) Challenging and disrupting deficit notions in our work with early childhood and elementary teachers. In D. Y. White, S. Crespo, & M. Civil (Eds.). Cases for teacher educators: Facilitating conversations about inequities in mathematics classrooms (pp. 113–120). Association of Mathematics Teacher Educators and Information Age Publishing.

Felton, M. D., & Koestler, C. (2012). “Questions and answers can mean something”: Supporting critical reflection in mathematics education. In R. Flessner, G. Miller, K. Patrizio, J. and Horwitz (Eds.) Agency through teacher education: Reflection, community, and learning (pp. 25–35). Rowman & Littlefield Education.

Koestler, C. (2012). Beyond apples, puppy dogs, and ice cream: Preparing prospective K-8 teachers to teach mathematics for equity and social justice. In A. Wager and D. Stinson (Eds.) Teaching mathematics for social justice: Conversations with educators (pp. 81–98). National Council of Teachers of Mathematics.

Other Media and Creative Activities 

Thanheiser, E., & Koestler, C. (2025, Aug. 7). Episode 129: Building community to center equity and justice in mathematics teacher education. [Audio podcast episode]. Amidon Planet. Hosted by Joel Amidon.

Thanheiser, E., Koestler, C., Sugimoto, A. T., & Felton-Koestler, M. D. (2025, May 13). Construct it! What’s in a name? Exploring identity through data. Illuminations Classroom Resources. NCTM.org

Koestler, C., Ward, J., Zavala, M. d. R., & Bartell, T. (2022, Sept. 22) Why use math to help young learners explore understand and respond to social injustice? Corwin Connect.

Dani, D., Koestler, C., & Chen, L. (2022, Summer). STEM integration in field experience for mathematics and science teachers. AMTE Connections: Integrating across disciplines and areas in mathematics teacher education, 5, 1–7.

Thanheiser, E., Koestler, C., Sugimoto, A., & Felton-Koestler, C. (2022, May 10). Connecting math to the real world [Video]. Featured at the 2022 STEM for All Video Showcase: Access, inclusion, and equity.

Dani, D., Hallman-Thrasher, A. H., Koestler, C., Lui, C., Sandler, N., Stigall, A., & Parsons, J. (2022, May 10). RALLY for STEM [Video]. Featured at the 2022 STEM for All Video Showcase: Access, Inclusion, and Equity.

Koestler, C., & Thanheiser, E. (2022, May 4). Building community to center equity and justice in mathematics teacher education [Audio podcast episode]. Teaching Math Teaching. Association of Mathematics Teacher Educators. Hosted by Joel Amidon.

Koestler, C. (2022, Jan.). Supporting LGBTQ+ Students and Families in Math Classrooms [Twitter Chat, #OCTMchat]. Ohio Council of Teachers of Mathematics.

Bartell, T., Koestler, C., & Foote, M. Q. (2021, Dec.) Mathematics teachers’ understanding of privilege and oppression [Audio podcast episode]. Mathematics Teacher Educator. Hosted by Eva Thanheiser.

Koestler, C., & Thanheiser. (2021, Dec. 15) If the world were a village: Learning mathematics while learning about the world [Audio podcast episode]. Mathematics Teacher Educator. Hosted by Eva Thanheiser.

Koestler, C., Jessup, N. & Thanheiser, E. (2021, May 3) Teaching is never neutral [Audio podcast episode]. Jabbedu. Hosted by Jonathan Ruths.

Koestler, C., Chao, T., and Yeh, C. (2021, Feb). Bringing identities in and inclusivity through mathematics story problems [Twitter Chat, #OCTMchat]. Ohio Council of Teachers of Mathematics.

Koestler, C., & Felton-Koestler, M. (2020, March 22) How to run math summer camps. Teaching Math Teaching. Association of Mathematics Teacher Educators. Hosted by Dusty Jones, Eva Thanheiser, and Joel Amidon.

Koestler, C. (2019, Oct. 30). Teaching is never neutral [Video]. Patton College of Education EDTalk.

Koestler, C. (2018, June 15). Encouraging invented algorithms to support more equitable and child-centered classrooms, Part 2 [Invited blog post]. My NCTM.

Koestler, C. (2018, May 30). Encouraging invented algorithms to support more equitable and child-centered classrooms [Invited blog post]. My NCTM.

Koestler, C. (2017, Nov. 28). Math and Science Teaching Challenges with Dr. Courtney Koestler [Audio podcast]. Teaching Matters. WOUB Public Media. Hosted by Scott Titsworth.

Koestler, C. (2011). A review of A mathematician's lament: How school cheats us out of our most fascinating and imaginative art form. Teaching Children Mathematics, 17(6), p. 378.

Externally-Funded Research Projects

• 2021 - Present: Principal Investigator (August 2024–present), Co-Principal Investigator (2021–2024)
  • Connecting Elementary Mathematics Teaching to Real-World Issues
  • Funded by the National Science Foundation
  • Collaborative Grant Total: $1,926,121
• 2018–2024 Co-Principal Investigator
  • Rural Appalachian Leaders and Local Youth for STEM
  • Funded by the National Science Foundation: $2,321,818
• 2018–2019 Principal Investigator
  • Moving with Math and Literacy
  • Funded by the Martha Holden Jennings Foundation: $9,189
• 2016–2017 Co-Principal Investigator
  • Scaffolding Inquiry and Problem-Solving through Literacy and Argumentation Strategies
  • Funded by the Ohio Department of Higher Education: $148,285
• 2016–2017 Co-Principal Investigator
  • SouthEast Ohio Math Teachers’ Circle 4.0
  • Funded by the Ohio Department of Higher Education: $50,116
• 2015–2017 Principal Investigator
  • Engaging in Classroom Inquiry to Create More Equitable Mathematics and Science Classrooms in Southeast Ohio
  • Funded by the Martha Holden Jennings Foundation: $36,989
• 2015–2016 Co-Principal Investigator
  • SouthEast Ohio Math Teachers’ Circle 3.0
  • Funded by the Ohio Department of Higher Education: $45,049
• 2014 -2020: Consultant (2014-2020), Key Personnel (2014)
  • Access, Agency, and Allies in Mathematical Systems (A3IMS)
  • Funded by the National Science Foundation: $2,532,254
• 2013–2014 Principal Investigator
  • Common Core Collaborative (C3): A Collaboration of the State Universities and Education Stakeholders in Implementing the Math Common Core in Schools Across Arizona
  • Funded by Arizona Board of Regents: $948,440
• 2011–2014 Co-Principal Investigator
  • Algebra Ready: Transitioning to Academic Success
  • Funded by Helios Education Foundation: $560,000
• 2010–2013 Key Personnel
  • Beyond Bridging: Co-Education of Preservice and Inservice Elementary
  • Teachers in Science and Mathematics
  • Funded by the National Science Foundation: $2,223,107