In order to investigate pre-service teachers (PSTs') understandings of the terms mathematics and numeracy, the authors conducted a study at one Australian university. The PSTs were enrolled in a mandatory unit about numeracy across the curriculum, in which both teachers' and students' numeracy capabilities were considered. The study took place from 2015 to 2019. Participants completed questionnaires before starting the unit (pre-unit questionnaire) and at the end of the unit (post-unit questionnaire), so that the authors could discern if their views had changed as a result of completing the unit. In this article, the authors report the findings from their analysis of the questionnaire data from PSTs completing primary (Foundation to Year 6) teaching qualifications.