This article reports a qualitative inquiry into school leaders' and teachers' rationales for teaching to develop students' "mathematical literacy." The study is rooted in an exploration of the meanings that the school leaders and teachers hold about the term mathematical literacy. Six leaders and three grade 9 mathematics teachers from three schools were interviewed. Analysis framed within cultural-historical activity theory indicates that mathematical literacy is perceived as a desired outcome of schooling, and that teaching for mathematical literacy is connected to school leaders' and teachers' contradictory rationales for teaching. The rationales are connected to use value, meaning, teaching practice, teacher competences and knowledge, and universality.