Abstract
Seen from an international perspective, the professionalisation of (prospective) teachers for inclusive education is a main determining factor for the inclusion-related further development of schools and classes in various subjects. However, the prerequisites for acquiring inclusion-related expertise and professionalism for designing inclusive teaching vary greatly from country to country. This is especially evident in the stratified secondary level of the education system in Germany. In this paper, we draw on the results of a study on the description and analysis with respect to the acquisition of expertise for inclusive mathematics teaching. Guided interviews were conducted with experienced mathematics teachers in inclusive teaching of the secondary level and analysed with qualitative methods. Among other elements, concrete tasks, assignments, and video vignettes from teaching were used as narrative-generating prompts. This paper elaborates on how the expertise and professionalism for inclusive mathematics teaching gained under ambivalent conditions can be described and what indications can be found for its acquisition. It pays special attention to the reflexive evocation and handling of contingencies as key moments for the further development of a teacher’s professionalism on inclusive mathematics teaching.