<p>In recent decades, educational reforms have introduced requirements for the digitalization of curriculum resources, including textbooks. Digital textbooks can offer new opportunities for teaching and learning mathematics through the provision of novel features such as interactivity, dynamics, feedback, and personalization. The aim of this paper is to examine how the digital potentials highlighted in the reform are reflected in digital textbook tasks and how these tasks are used in classroom practice. The study encompassed the analysis of the three digital textbooks for middle grades in Croatia, including all 3363 e-tasks, and a multiple case study of six teachers and their classes. To answer the research questions, a comprehensive framework was developed with the aim of analysing the e-tasks in terms of their digital potentials. The results showed that, in line with curriculum requirements, the tasks included interactive quizzes, dynamics, and automated feedback. However, digitalization was not being employed to its full potential. Classroom observations indicated that digital textbooks were primarily used to display static images on a smartboard screen. Additionally, the findings suggest that the main users of digital textbooks were mathematics teachers using frontal teaching and Guide-and-explain orchestration.</p>