This paper compares and contrasts cases of three beginning teachers, graduates of a teacher education program that included an intervention component designed to change prospective elementary teachers' knowledge and beliefs about mathematics education. The goal of the intervention (a sequence of three mathematics courses, a methods course, and a curriculum seminar) was to develop a more conceptual level of knowledge about mathematics itself and about the learning and teaching of mathematics. Each subject is described as both student and teacher of mathematics. Analysis focuses on ways in which knowledge and context influenced choices made by these novice teachers. Each new teacher faced responsibility for teaching multiple subject matter; deciding on the mathematical content children should have an opportunity to learn; creating mathematical tasks; and using instructional time given multiple and competing goals. Differences appeared in choices made in response to these issues. Choices were influenced by an interaction of views about knowledge and pedagogy and the degree to which context was perceived as a constraint. A question is raised regarding the nature of support required in the induction years if new teachers are expected to institute practices that are innovative and difficult to implement, questioned in traditional school settings, and unfamiliar to faculty, administrators, parents, and students. (Author/LL)