This paper examines how a teacher-led cluster of rural schools used evidence of student achievement to improve the quality of learning opportunities for students in mathematics. The teachers began to collect evidence in order to promote constructive dialogue and stimulate action. An inquiry cycle provided feedback to schools through the cluster members. The students' results show that in two terms most of the five schools were able to accelerate progress in basic facts and place value. When the teachers' written intentions are considered alongside these results it appears that emphasising the broader mathematical context of these basics may have been more effective than practising them in isolation.