This study began as an investigation into the experiences of five students making the transition from secondary teaching assistant to specialist teacher of secondary mathematics, via a local degree programme set up specifically. The development of a degree for the teaching assistants (who were required to work in schools throughout their study) forced me to address how work-based learning plays out in the context of developing knowledge for teaching, in this case, mathematics knowledge, when the learner is operating in simultaneous workplaces, at school and at university. It became clear that I was straddling a disjuncture between working and learning practices that pervaded all aspects of the project: the teaching assistants' work, and their ambition to become graduates; the structure of the degree itself; relations between university mathematics and the working world of school mathematics; and within my own attempts to learn from research in the same arena that I was working in as a teacher. The study provides an illustration of exposing a new constituent and previously excluded group of students into a traditional curriculum. I argue that knowledge acquired about learning informally through work is critical with respect to successful mathematics learning at university for these teaching assistants, although this raises questions of curriculum relevance. This being so, learning through work as a precedent to academic study may deserve more attention within strategies to widen participation. I also raise questions as to the readiness of traditional universities for new student groups, and the extent to which informal learning is recognised as a significant aspect of successful experience.