This study presents part of a research project that aims to develop prospective mathematics teachers' Technological Pedagogical Content Knowledge (TPCK). The project considers various TPCK components. This report focuses on a particular component, namely the "knowledge of using multiple representations (MRs) with technology". A course was designed using the TPCK framework, and forty prospective mathematics teachers took part in the course. They were enrolled in a teacher preparation programme in a state university in Istanbul, Turkey. As part of this course, prospective teachers participated in workshops during which they were introduced to the TPCK framework, which was illustrated using function and derivative concepts. The workshops included examples of MRs, how to make links among them, and the way in which technology could contribute to achieving the intended linkages. Following the introductory workshops, the prospective teachers themselves prepared and carried out similar workshops for their peers with different topics including limit, continuity, probability, radian and integral. They were grouped into fours, assigned one of these topics and asked to prepare the workshops in collaboration. The participants also prepared lesson plans and teaching notes and performed micro-teaching (during which they taught lessons to their peers as if they were in a real classroom environment). Following the completion of the course, the authors attempted see the participants' development with regard to using multiple representations (MRs) with technology. For this purpose, the authors found the functional taxonomy of MRs proposed by Ainsworth (2006) useful in that it allowed them to see development of the participants through the course activities, as well as to perform comparative analyses of participants' developmental trajectories.