With increased accountability attached to students' results on national testing in Australia, teachers feel under pressure to prepare students for the tests. However, this can lead to shallow teaching of a narrowed curriculum. An alternative approach involves using data to identify common errors and misconceptions, discussing strategies aimed at building understanding of important mathematical ideas as well as students' confidence in answering context-based mathematics questions. This study explored the use of a learning model based on professional conversations about national testing results as well as school-based assessment data with junior secondary mathematics teachers in one school. The teachers identified the learning needs of students and chose to implement mental computation and estimation approaches as well as a strategy to address the literacy demands of numeracy test items to support student learning before and after the NAPLAN test. An analysis of the professional learning model identified approaches to enhance both student learning and teaching practice. (Contains 7 tables and 3 figures.)