Building on recent research into the importance of positive teacher emotions for student learning experiences, the current study involved five upper primary teachers at a Victorian government school developing integrated mathematics units built around topic areas of personal interest or passion. Respective students (n=88) elected to participate in one of five structured inquires developed by these teachers. Participation was associated with increases in students' intrinsic motivation to learn mathematics. Students attributed positive evaluations to the opportunity to learn mathematics in a context in which they were personally engaged. Possible future research directions are discussed.