Evolving Conversations in Mathematics Curriculum Research

A curriculum is a living, socially mediated set of materials that both reflects and shapes what counts as mathematics and who is positioned to learn it (Ball & Cohen, 1996; Remillard, 2005; Rezat, 2012, 2024; Smith & Barrett, 2017). Previous mathematics curriculum studies have revealed that what often appear as “differences in content organization” are, in fact, differences in the purposes that curricula serve within distinct educational traditions (e.g., Bütüner, 2021; Yang et al., 2025; Zhou et al., 2022; Lo et al., 2024). This realization has shaped our ongoing inquiry into curriculum research scope, methodology, and impacts, moving beyond surface-level comparisons toward broader interpretations of how and what mathematical knowledge is selected, organized, and experienced (Stein et al., 2007).

For this Special Issue on mathematics curriculum research, we invited diverse contributions that interrogate curriculum’s role in mediating learning opportunities, fostering equity, and responding to social and institutional contexts. The contributing authors, representing Croatia (Pleština et al., 2025 [Contribution 6]), the United Kingdom (Golding, 2024 [Contribution 3]), South Africa (Khoza & Ngcobo, 2025 [Contribution 4]), and the United States (Edson et al., 2025 [Contribution 1]; Huntley et al., 2024 [Contribution 2]; Lo & Zhou, 2025 [Contribution 5]; Stone et al., 2025 [Contribution 7]), bring rich international perspectives to this conversation. The eight papers featured here provide theoretical, empirical, and practical insights across nations, curriculum types, and levels of schooling. Together, they present a multifaceted portrait of curriculum as a dynamic and critical component of mathematics education. Collectively, the eight publications illuminate the following three themes: (a) curriculum content and design, (b) curriculum policy, implementation, and influence and equity, and (c) culture and the purpose of curriculum.

• Mathematics Curriculum Content and Design

Several papers in this Special Issue delve into the substance and structure of mathematics curriculum content, revealing how curricular design shapes students’ learning experiences. Lo and Zhou’s (2025) [Contribution 5] study focuses on how textbooks structure a small topic (the relationship between area and perimeter), which highlights how different instructional sequences in two U.S. textbooks can shape students’ conceptual understanding. Huntley et al. (2024) [Contribution 2] investigate 63,000 algebra problems in U.S. high school textbooks, identifying substantial differences in cognitive demand, content sequencing, and the integration of real-world contexts. Feedback from textbook authors provides rare insight into how design choices reflect underlying educational philosophies and priorities. Pleština et al. (2025) [Contribution 6] trace the historical evolution of polynomial knowledge within Croatian high school mathematics, showing how shifts in curricular frameworks influence the coherence between algebraic and analytical reasoning. These works illuminate the complexity of content design and underscore the diverse epistemological and pedagogical assumptions embedded in curriculum materials.

• Curriculum Policy, Implementation, and Influence

Another cluster of studies examines the dynamic interactions between curriculum policy, classroom enactment, and educational outcomes. These contributions foreground the interconnectedness of curriculum design, teacher learning, and student achievement, showing that curricular reform is not merely a matter of content revision but also of professional and institutional mediation. Golding’s (2024) [Contribution 3] study provides a longitudinal account of mathematics curriculum implementation in England, illustrating how teachers, edu-businesses, and even learners act as policy mediators who reinterpret and reshape curricular intentions. Similarly, Edson et al. (2025) [Contribution 1] examine teacher perceptions of a field-test version of the fourth edition of Connected Mathematics in the United States, highlighting the importance of iterative curriculum development grounded in classroom realities and emphasizing the interconnectedness of curriculum design, teacher learning, and student outcomes. In the South African context, Khoza and Ngcobo (2025) [Contribution 4] highlight how school leaders’ decisions around curriculum adoption can influence instructional coherence across contexts. Together, these papers deepen our understanding of curriculum as a negotiated space that is continually reinterpreted through the practices and perspectives of multiple educational actors.

• Equity, Culture, and the Purpose of Curriculum

Another group of papers brings a critical and cultural lens to mathematics curriculum studies, addressing the extent to which curriculum can serve as a vehicle for equity and empowerment. Stone et al. (2025) [Contribution 7] develop and apply the Culturally Responsive Mathematics Materials Evidence Tool (CRM-MET) to analyze middle school curricula, revealing substantial gaps in how power, participation, and cultural identity are represented. Zelkowski et al. (2025) [Contribution 8] describe a long-term, structured professional development model that empowers teachers as leaders and change agents in high-need schools, demonstrating that curriculum engagement can promote both instructional growth and social justice-oriented leadership. These studies collectively argue that curriculum is not neutral; rather, it embodies values, voices, and visions of who can participate in mathematics and how.

This Special Issue contributes to the evolving conversation about what mathematics curriculum is and what it can become (Herbst et al., 2023). It invites researchers, teachers, and policymakers to view curriculum not as a finished product but as an evolving practice shaped by educators’ interpretation and institutional structures. Echoing the insights of Aguirre et al. (2024) and Fan et al. (2025), the works collected here remind us that curriculum research is most powerful when it bridges theory and practice, challenges taken-for-granted assumptions, and envisions mathematics learning as an inclusive and transformative endeavor. We hope this Special Issue inspires continued dialogue, critical reflection, and collective action toward more coherent, equitable, and responsive mathematics curricula worldwide.