Ivy, Kelly KristinaWhile many educational institutions have updated their strategic plans mandating culturally responsive teaching (CRT) or culturally relevant pedagogy (CRP), mathematics teachers are reluctant to embrace CRT/CRP, approaching the teaching and learning of mathematics from deficit paradigms that reflect the pedagogy of poverty. Culturally responsive mathematics teaching (CRMT) is necessary because it promises to promote meaningfulness for, accessibility to, and high levels of engagement with school mathematics for Black, Latinx, and other historically marginalized students. However, to date, there have been numerous theoretical arguments for, but few empirical examples of CRMT, and, as a result, many mathematics teachers are uncomfortable employing CRMT. This qualitative case study examines how an experienced and highly regarded Black urban middle school mathematics teacher (Ms. Collier) understands the theoretical and empirical literature on CRP and how she changes her teaching during and after implementing a CRP curriculum unit with her Black and Latinx students. In the context of this study, I offer Ms. Collier’s journey of embracing CRMT by “remixing” her mindset as a mathematics teacher by reading and discussing CRP and CRMT literature and then remixing her curriculum and instruction in response to her “remixed” understandings. In sum, using frameworks such as Culturally Relevant Pedagogy, Culturally Responsive Mathematics Teaching, and Teacher Change Theory, I explored Ms. Collier’s theory-to-practice applications of CRT. The dissertation results are organized into two parts corresponding with different study phases. Part 1 focused on Ms. Collier’s fine-tuned understanding of CRP, and Part 2 focused on Ms. Collier’s perspectives on her experiences implementing CRMT with her Black and Latinx students. Data were collected from four sources: conversations, semi-structured interviews, written reflections, and memos. Key findings indicate that Ms. Collier was, in fact, a Dreamkeeper, understanding Ladson-Billings’ foundational CRP tenets of Academic Achievement, Cultural Competence, and Critical Consciousness. Findings also crystallized two new tenets of CRP I advance that are present but not explicitly named in the literature: Classroom Domain and Teacher Mindset. In addition, salient themes demonstrating each domain of Teacher Change Theory emerged, with Ms. Collier experiencing a meaningful change in perspective: It's about the curriculum AND who the person is. With this study, I challenge the idea of reducing CRP to a set of practices. My stance is that CRP is more so a process of being for the teacher because this body of work studies the more significant issue of mathematics education for Black and Latinx students. As a mathematics teacher who understands the many stereotypes and stigmas that Black and Latinx students face in the learning and doing of mathematics, Ms. Collier expressed a clear awareness of the impact that culturally relevant instructional and relational practices could have on her Black and Latinx students.enDissertationMathematics educationCulturally Relevant PedagogyCulturally Responsive TeachingMathematicsTeacher Change TheoryUrban Education