Discussions of race in educational research have focused primarily on performance gaps and differential access to advanced coursework. Thus, very little is known about how race mediates the learning process, particularly with respect to classroom participation and student identity formation. This dissertation examines mathematics learning as a context for illuminating the racial dynamics of learning in everyday classroom activity. Although mathematics and race may seem strange bedfellows, a poststructural analysis reveals specific linkages between them that suggest that their discourses are actually well aligned. To conceptualize this alignment, this dissertation introduces the theoretical frame of "racial-mathematical discourse," which establishes the groundwork for the empirical investigation reported here. Observations took place in four mathematics classrooms at a racially diverse high school over the course of a school year. Interviews (n=35) were conducted with students from the focal classrooms. Data were analyzed to explore how students make sense of racial-mathematical discourse, and to gauge the discourse's impact on learning. Findings indicate that racial-mathematical narratives were central to students' sense making. All students reported awareness of the "Asians are good at math" narrative, as part of a web of racial ideology. Importantly, students linked it to narratives about other groups' mathematical inferiority (e.g., "Blacks are 'bad' at math"). They also connected racial-mathematical narratives to broader racialized discourses outside mathematics (e.g., perceptions of intelligence). Students observed the presence of these narratives in locations outside the school setting, such as media imagery and international comparisons. Data further suggest that racial-mathematical discourse is not a static belief system. Rather, it emerges and is reified as students engage in typical classroom practices, such as noting which classmates get asked for help. This is consequential for learning, in that the deployment of racial narratives in social interaction frames students' opportunities to build identities as capable learners. This dissertation develops a framework leveraging insights from sociocultural and poststructural theory to trace the impact of racialized classroom episodes on students' identity formation. It highlights critical issues that need to be taken into account in the design of equitable learning environments, especially for students of color from persistently marginalized backgrounds. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]