Mathematics for Curriculum Leaders involves teachers in a deliberate enquiry into the nature of understanding in mathematics and the ideas underlying its teaching and learning. Helping children with the language of mathematics is shown to play an important part in mathematics teaching. The pack is divided into 7 units drawing upon the demands of the National Curriculum and providing activities to support children in their attempts to report their thinking. Sensitive collection and interpretation of this information in order to guide action is an essential feature of each unit.