Various curriculum resources have emerged over the last decades, but the textbook still remains the most used teaching and learning resource in mathematics classrooms. In this paper, we use a case study to analyse the teaching practice of one mathematics teacher. The aim of the study is to examine how the mathematics teacher interacts with the textbook and teacher guide, especially focusing on when the teacher offloads resources from the textbook, adapts resources, or improvises in the classroom. The study was conducted using lesson observations and semistructured interviews. The results showed that the teacher does not favour a particular type of resource mobilization. Her interaction with the given resources can be characterized as a dynamic interplay, where the type of resource mobilization changes from lesson to lesson as well as within lessons. Moreover, the teacher's mobilization of the textbook and the teacher guide depends on the teacher's goals and her assessment of what provides the most pedagogically beneficial instruction for the students.