Over the last decade many western countries have undertaken educational reforms in an effort to increase student achievement in mathematics. In New Zealand the government funded the Numeracy Development (NDP) a professional development initiated in 1999 in response to student under-achievement in the TIMSS mathematics tests.This book investigates the intentions of NDP in relation to the perspectives of eight teachers who participated in this mathematical reform programme. The teachers' perceptions of their experiences are considered in relation to the baseline intentions of NDP.The book provides a rationale for the necessity for mathematical reform in NZ schools. It details the intentions of NDP and outlines nature of the programme designed to enable participating teachers to make change. The teachers describe their perceived successes and challenges in their attempt to embed the mathematical reforms. They voice examples of their growth in knowledge and pedagogy and talk about their frustrations over lack of time to consolidate these changes. This book is written for teachers involved in professional development, researchers, facilitators and lecturers in mathematics education.