Summary: Understanding place value: A case study of the Base Ten Game was the research focus of nine teachers from five diverse schools in the independent sector in South Australia. The project explored the role of a commonly used teaching activity, referred to in this report as the Base Ten Game, in developing children{MARC-8 Generic 224}s understanding of our number system. This activity, based on a game described by Pengelly (1991) was selected because it models the structure of the number system, with students using a place value board and concrete materials to explore progressively larger, or smaller, quantities. The research project was conducted over Terms 2 and 3 in one school year