It is a known fact that South African learners underachieve in mathematics. One possible factor that might have an influence on their mathematics achievement is the conceptual knowledge of mathematics teachers. In order to facilitate conceptual understanding, mathematics teachers themselves must possess profound mathematical knowledge. One key aspect of the complex landscape of pre-service mathematics teacher education is the development of pre-service teachers' mathematical knowledge. Various studies have suggested that pre-service teachers need to be exposed to the meaningful learning of mathematics as a way to develop their mathematical knowledge for teaching. By using a mixed methods approach, this study examined the influence of a technologically enhanced learning environment on the conceptual understanding of mathematical functions of pre-service mathematics teachers. Using a hybrid model of O'Callaghan's framework and Dreyfus's typology, pre-service teachers were tested on the modelling, interpretation, translation and reifying of functions. Data were gathered from a pre-post-test, as well as from task-based interviews. The results revealed that there was no improvement in the first three components, but a significant improvement in the reification component.