In 2001, with funding of $7 million, the Australian Government implemented the "Numeracy Research and Development Initiative"--one of several initiatives introduced by the Australian Government to support literacy and numeracy improvement. Other initiatives included the "National Indigenous English Literacy and Numeracy Strategy," and the "Quality Teacher Program." The "Numeracy Research and Development Initiative" comprised two complementary strands: a national project strand and a strategic States and Territories projects strand. The purpose of these projects was to investigate a broad range of teaching and learning strategies that lead to improved numeracy outcomes. This article highlights the findings of the "Numeracy Research and Development Initiative" projects. The initiative has resulted in a deeper understanding of key issues surrounding numeracy education and has also opened up new opportunities for collaboration between universities and education sector authorities. The success of the numeracy projects has demonstrated the potential for research studies where teachers can participate as partners in research while engaging in their own professional development. A key outcome for the teachers involved in the projects has been the growth in their mathematical pedagogical knowledge and also in their own deeper understanding of the mathematical concepts they were teaching. These findings can be seen to have implications for numeracy teaching and learning at all levels of organisation, from government education policies to school administration and classroom practice.