This paper explores the potential of participatory action research to bring about significant changes in practice in a context in which more conventional approaches to research have had limited impact. It focuses on secondary mathematics classrooms where teaching approaches characterised by memorising and practising mathematical procedures, with little understanding of their application, purpose or underlying concepts, remain commonplace in many countries around the world and have proved highly resistant to change. The paper highlights the damage caused by such practices in terms of the alienation of large numbers of students and the inequitable outcomes they are associated with, including the strong correlation that persists between studen...