Lena Wessel develops principles for designing subject- and language-integrated support materials as well as language-sensitive interaction processes. The analysis of the developed support materials forms the core of her qualitative case studies and demonstrates that selected mathematics didactic approaches can be effectively combined with language didactic approaches. Furthermore, the author highlights potentials for integrated support of subject-specific concepts and topic-related linguistic resources through qualitative in-depth analyses. In the area of "Fractions and Ratios," it becomes clear that substantial results can be achieved with relatively few support sessions.