This article aims to illustrate how the collective resolution of routine mathematical tasks can give rise to uncertainties, fostering and supporting a rich and authentic mathematical activity. While solving routine tasks may not typically be classified as problem-solving, the research presented in this paper shows that, at the collective level, their resolution can give rise to new mathematical tasks to solve in the classroom and generate authentic problem-solving activity. Grounded in the enaction theory of cognition (e.g. Maturana & Varela in Shambhala, 1992), this research considers the class as a unit, as a collectivity, which brings forth a mathematical activity. In this article, examples derived from an experiment conducted in elementary-level mathematics classrooms are used to show the emergence of uncertainties, highlighting the mathematical potential resulting from the collective resolution of routine tasks. In conclusion, the article introduces the concept of "collective mathematical problems."