How to facilitate students’ understanding of science’s abstract concepts is definitely a major concern of every dedicated physics teacher. However, discussions about promising ways to be successful at this task are not always part of teacher training curricula. With the goal of contributing to the research in this field, we have analysed a set of lectures given by a distinguished physics professor. In this proposal we present the analysis of two lectures where the abstract concepts of charge density and electric flux are taught. The complexity of the mathematization of these concepts is evident both by the considerable amount of time dedicated to it and by the different strategies used by the professor in his exposition. These strategies are described and exemplified. Using the software videograph for the video analysis, we were able to identify the specific instants where each strategy takes place as well as their duration and interplay. This dynamical process is visualised with the aid of a timeline
generated by the program. In general, our analysis evidenced that the professor adopted a “concrete to abstract” approach, made an extensive use of visual representations and concrete analogies, mentioned idealizations explicitly and made punctual metacognitive remarks. Taking into account the future perspectives of our research, the categorization of the didactical strategies used by this professor shall allows us to develop comparative studies with other lectures on the same topic. Moreover, the derivation promising strategies to teach the structural role of mathematics in teacher training courses is also aimed at by this research.