With consistently low levels of academic performance and high rates of absenteeism (Bourke & Rigby, 2000), the students in this study are the most educationally disadvantaged group in Australia with respect to mathematics. This paper reports on a study undertaken with Years 5-7 students in a Queensland aboriginal community to determine their baseline knowledge of whole numbers. The results of a numeration test were analysed to identify major misconceptions, and selected students were interviewed to establish whether misconceptions were language-, context-, or mathematics-based, and then to "peel back" to culture-specific language and activities if language and concept proved to be the main sources of misconceptions. The interviews revealed that misconceptions were generally related to language and mathematics schema. (Contains 2 figures and 2 tables.) [For complete proceedings, see ED500859.]