Marina PapicThis project assesses the underlying mathematical knowledge of 53 children from two Sydney pre-schools, one year prior to formal schooling, and monitors their on-going mathematical development. The ability to generate and abstract simple mathematical patterns is explored through a range of problem-solving tasks. Data comprise structured videotaped individual interviews, children?s representations, observational and anecdotal records. A case study of one pre-school analyses an early mathematics intervention program highlighting mathematical patterns, structures and relationships. The study analyses teacher and community perceptions; the effectiveness of this intervention on children?s mathematics learning, the professional development of pre-school staff and their programs.