The aim of this article is to highlight the experiences of 11–12-year-old students at a Norwegian primary school regarding their use of Minecraft in mathematics classes and explore the consequences for their motivation. The present research was carried out as a single case study. This implies an in-depth investigation of a contemporary phenomenon, an intervention, studied in its real-life context, the classroom. The object of the intervention in the participating class in 2015 and the spring of 2016 was to use Minecraft as an attempt to restore motivation for mathematics. The teacher found his students were motivated to work with Minecraft, but a question emerged about students' motivation to perform the given tasks. This study suggests that formative interventions in which the researcher is present in a school context implicates the possibilities for the study of externalisation processes. These processes provide an opportunity to obtain an understanding of what happens when a popular digital game from youth culture is applied to tasks in mathematics to achieve pedagogical goals.