Norwegian classrooms have become more culturally diverse due to immigration. School mathematics is frequently misperceived as the subject least impacted by demographic changes. In this paper, we draw on two important concepts -- "identity" and "culture" -- to explore how children of immigrant background construct their identities as mathematics learners. Data collection include classroom observations, focus groups, and individual interviews with three 12-year-old children in Oslo: Amar, Laila, and Maya. Thematic analyses yielded four themes around which pupils construct their identities. The first two regard positioning of the self in the mathematics classroom, and future-oriented self. The latter are concerned with family-related issues: parents' role in identity construction, and mathematical methods used at home. Finally, we discuss how our work opens avenues for further investigations.