The moment-to-moment dynamics of student discourse plays a large role in students' enacted mathematics identities. Discourse analysis was used to describe meaningful discursive patterns in the interactions of 2 students in a 7th-grade, technology-based, curricular unit (SimCalc MathWorlds[R]) and to show how mathematics identities are enacted at the microlevel. Data indicated that students' peer-to-peer discourse patterns explained the enactment of differing mathematics identities within the same local context. The ways that people talk and interact are powerful influences on who they are, and can become, with respect to mathematics. (Contains 2 footnotes, 8 tables, and 2 figures.)