This study offers an account of ways in which "ritual" (McCloskey, 2014) serves as a lens for identifying societal and cultural patterns related to mathematics teaching and learning in present-day US classrooms. We use data from an ethnographic study of a fifth grade mathematics classroom in which a student teacher and a mentor teacher shared responsibility for teaching a fractions unit. Using the analytic framework of ritual, we highlight the cultural nature of teaching, learning, and learning to teach mathematics. We use classroom observations and interview data to identify instances of each of the four aspects of ritual and draw on Gregg (1995) to suggest cultural patterns at work in this classroom. Our analysis and interpretation illuminate aspects of the complexity of teaching, learning, and learning to teach mathematics.