Teachers' understanding of the elementary school mathematics curriculum forms part, but not all, of the newly emerged field of mathematics for teaching, a term that describes the specialised mathematics knowledge of teachers. Pre-service teachers from a one-year teacher preparation program were studied in each of three years, using a pre-test/post-test survey of procedural and conceptual knowledge of mathematics required by elementary teachers. Beliefs about mathematics were also examined through post-test interviews of 22 of the participants from one of the cohorts. Each cohort of teacher-candidates was consistently found to be initially weak in conceptual understanding of basic mathematics concepts as needed for teaching. The pre-service methods course, which included a strong focus on specialised mathematical concepts, significantly improved pre-service teachers' understandings, but only to a minimally acceptable level. Program changes, such as extra optional course in mathematics for teaching, together with a mandatory high-stakes examination in mathematics for teaching at the end of the methods course, have been subsequently implemented and show some promise. (Contains 2 tables, 2 figures, and 1 footnote.)