Linking proportionality of arithmetic, algebra and geometry domains in Indonesian lower secondary textbooks

The aim of this study is to use the notion of praxeology, developed in the framework of the anthropological theory of the didactic (ATD), for textbook analysis. Our focus is the treatment of proportion in arithmetic, algebra and geometry domains in Indonesian lower secondary textbooks. The results show that ATD can be used to build a reference model to analyse the type of tasks proposed in textbooks. Furthermore, the analysis is useful to capture a link between these three domains