This paper presents a study on the approach to functions, whose focus was on gestural activity, and which was carried out with students from a Chilean university who were studying Calculus I. Theory of Objectivation and Comognitive Theory were considered as theoretical referents. The results obtained showed the relevance of the discourse that is produced through gestures in the collective activity, contributing to the generation and emergence of key mathematical elements of the object function of real variable. In this context, gesture was the driving force behind the mathematical discourse of the semiotic system of cultural significance. In addition, this study made evident the breakdown of the traditional discourse of mathematics teaching at the university level as an important factor.