The aim of this master thesis was to describe and analyze how subtractions are made visible through illustrations in mathematics textbooks for Swedish first grade pupils (the pupils seven years old) and how pupils make use of illustrations in subtraction operations in mathematics textbooks. The study was based on two empirical parts. First a textbook analysis of the 21 textbooks from twelve different textbook series, which are the most used in Swedish mathematics education, was made. Secondly video observations from twelve pupils who, in pairs, discussed five selected illustrations were made. The empirical material was analyzed using subtraction situations (Fuson, 1992) and affordances (Gibson, 1986). The textbook analysis showed that more than 85 percent of the illustrations derived from a Change take from situation (Fuson, 1992) and that the variation between different textbooks both considering subtraction situations and affordances was large. A conclusion drawn from this was that the selected textbook is of great importance. The analysis of the video observations showed that the pupils sometimes discover the aimed subtraction situation and/ or affordance and sometimes not. This influences how pupils handle the mathematical operations. A conclusion of this was that pupils have to discover the aimed subtraction situation as well as the aimed affordance to be able to handle a mathematical operation in the textbook in a desirable way.