In this article we explore similarities and differences between two school subjects, Norwegian and mathematics, taking a phenomenological perspective and a didactic meta-perspective (literacy perspective). Our argument is presented on three levels which together build on the perspective of meta-language. First we consider the level of discourse primarily concerning cultural relations and communities of meaning, for example subject-related communities. The next level is genre, concerning both "common cultural texts and practices and how meanings are framed in linguistic forms." Finally, we consider arguments regarding the modes of thought which underpin subject-specific learning. Substantiated by data from own classroom research, we argue that cross-curricular work needs to understand both differences and similarities between subjects, and the relationships between them. (Contains 1 figure.)