Becoming a Shape, Becoming Yourself: Geometry, Identity, and Belonging in an Early Childhood Classroom

Authors

• Eva Thanheiser, Portland State UniversityFollow
• Molly Robinson, Portland State University
• Simon Byeonguk Han, Portland State University
• Amanda T. Sugimoto, College of Education Portland State University USA
• Courtney Koestler, Ohio University
• Mathew D. Felton-Koestler, Ohio University

Author ORCID Identifier(s)

Eva Thanheiser (0000-0003-2970-5111)

Sponsor

This material is based upon work supported by the National Science Foundation, under Grant Nos. 2101456 and 2101463. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Published In

Contemporary Issues in Early Childhood

Document Type

Article

Publication Date

1-1-2026

Subjects

Early Childhood Classroom

Abstract

This paper examines how a first-grade geometry lesson became a site for exploring shape, selfhood, and belonging in an early childhood classroom. Drawing on interaction analysis of a lesson built around the picture book The Greedy Triangle , we show how children named personal strengths, identified shapes, followed a triangle through changing categories, reflected on why they liked being themselves, and used their bodies to form polygons. We ask what counts as mathematical activity in this lesson and argue that mathematics is not limited to naming shapes. It also involves noticing attributes, negotiating criteria, tracking transformation, coordinating bodies, and reasoning about recognition. We develop categorical belonging as an analytic construct for describing how children explore what something is, how it belongs to a category, and how it remains recognizable amid change. The analysis shows that everyday classification practices can become mathematical, embodied, and relational opportunities for children to negotiate recognition, difference, transformation, and belonging.

Rights

Copyright (c) 2026 The Authors

This work is licensed under a Creative Commons Attribution 4.0 International License.

Locate the Document

https://doi.org/10.1177/14639491261480601

DOI

10.1177/14639491261480601

Persistent Identifier

https://archives.pdx.edu/ds/psu/45319

Publisher

SAGE Publications

Citation Details

Thanheiser, E., Robinson, M., Han, S. B., Sugimoto, A. T., Koestler, C., & Felton-Koestler, M. D. (2026). Becoming a shape, becoming yourself: Geometry, identity, and belonging in an early childhood classroom. Contemporary Issues in Early Childhood.