Drawing upon recent theorising of numbers and data, and applications to schooling, this paper reveals how tensions between more accountability-oriented logics, and more contextually-situated conceptions of engagement with data, played out in one school in a regional community in northern Queensland, Australia. The research reveals that at the same time teachers' work and learning were heavily influenced by more reductive processes of quantification to account for teachers' practices, teachers also sought to draw upon the attention to numeric markers of student achievement to foster more substantive teacher learning for student learning. These tensions were expressed in relation to: efforts to foster improved student learning through collection of evidence via 'short-term data cycles'; engagement in various 'data conversations' with senior members of staff, and coaching by more experienced teachers, and; broader teacher learning initiatives focused on enhancing outcomes for specified groups of students identified as able to perform at higher levels of attainment. The research cautions that such practices present a quandary; even as broader processes of quantification of education may stimulate instances of more ongoing, substantive teacher learning for student learning, more performative applications of these numbers and data mitigate against the educative potential of such practices, and substantive learning for all students.