In order to maximise children's mathematical learning opportunities in school, we need to take account of what they have already learned about mathematics in their out-of-school contexts. Children's representations provide one such mechanism for gaining insight into their everyday mathematical experiences and understandings. This study utilises an ecological theoretical framework to examine the ways in which children's everyday experiences in a range of contexts influence their early mathematical understandings. Data is presented from a study of 100 four to six-year-old Australian children as they entered and experienced their first year of primary school. Throughout the study, the children completed a series of drawing tasks related to different mathematical concepts, and were invited to provide either verbal or written narratives to accompany their drawings. These data were analysed using an ecological theoretical framework in order to explore the individual components of each context, as well as the relationships between these contexts. Findings demonstrate that children come to school with rich understandings of mathematics which have been shaped by their experiences in a range of contexts. The activities and relationships within children's home settings appear to be the most profound in terms of developing mathematical understandings, with very few children representing mathematics learning within a school context.