The aim of this three-year study is to further contribute to the understanding of how relations between Reality – Theoretical models – Mathematics are communicated in different kinds of instructional situations (lectures, problem solving and labwork) in Swedish uppersecondary physics. A developed analytical framework from the pilot (Hansson, Hansson, Juter & Redfors 2015) is used to focus the analysis of the classroom communication on relations made (by teachers and students) between Reality – Theoretical models – Mathematics. Results from classroom studies during spring 2018 will be reported and discussed at the conference.