This article reveals the multiple ways in which data are constituted as a vehicle for governing teachers' work and learning. Drawing on the concept of governance, including in relation to the sociology of numbers, and data from one school in Queensland, Australia, the research reveals how teachers' work and learning were constituted through practices of: establishing specific 'targets', including various 'audacious goals' for school and national testing; focusing upon 'aligning' all forms of school, regional and national data collected within the school; and participating in various 'data conversations' about specific students with senior members of staff. While the research reveals how teachers found such practices beneficial for improving their practice with students, it also shows how this learning was always and everywhere framed within a broader discourse of data, and how this data-centric focus came to constitute what was valued about their work and learning, and that of their students.