The aim of this study is to deepen our understanding of the practice of a lecturer in linear
algebra by exploring the connections he makes between his content knowledge and his pedagogical
content knowledge while working on the topic of matrices. Data were collected through video
recordings of his classes and semi-structured interviews, and were analysed with the Mathematics
Teacher’s Specialised Knowledge model. Instances of classroom performance, supported by the
teacher’s own affirmations, provided evidence relating to the categories comprising the model, and
enabled us to establish connections between the lecturer’s knowledge, his understanding of his
students’ learning capabilities, and his knowledge of teaching mathematics, which together account
for his classroom practice: the use of varied examples to introduce new content, the highlighting of
the most salient aspects of the topic, and alerts about potential errors and difficulties. The contribution
that these results could make to the training of university teachers, which would be done with the
knowledge of the areas of difficulty shown by the teacher in mind, could be used to deepen other
elements of their pedagogical content knowledge. The interconnections between areas of knowledge
identified by the study also serve to validate the usefulness of a theoretical model for studying
teachers’ knowledge