In August last year, 167 principals gathered in Shepparton, north-eastern Victoria, to participate in the first of twelve modules of leadership training, developed by the Hume Region of the Victorian Department of Education and Early Childhood Development. The training program, called the Common Curriculum, reaffirms principals as instructional leaders in their schools. The first two educational leadership modules deal with numeracy education. This paper covers the content from the first module, examining how principals can help teachers to improve the numeracy skills of individual learners.