An often-misunderstood aspect of learning, parental engagement is key to children’s learning across all subjects. However, mathematics especially is perceived as an area in which out-of-school and home learning is absent. Tim Jay and Jo Rose, the authors of Parental Engagement and Out-of-School Mathematics Learning, confront this misconception. The authors conclusions are drawn from two large research projects that investigate both children’s and their parents mathematical thinking and learning outside of school, ‘discovering’ the mathematics involved in everyday activities. The practical and theoretical findings demonstrate a new approach to educational research that subverts and disrupts traditional models and approaches to help harmonise school and home learning. Challenging preconceived ideas and supporting children to acquire mathematical understandings, Parental Engagement and Out-of-School Mathematics Learning informs innovative and vital educational policy and practice.