This article deals with some questions related to the promotion of cultural learning processes in younger children (4–7 years old). In the study here reported, the promotion of mathematical activity was taken as the domain of study. Reasoning from a Vygotskian point of view, it was assumed that these learning processes should be embedded in the play activity of these children, and that these learning processes could be based on the children's ways of dealing with symbols/symbolic representations and meanings. In this observational study (according to case study methodology) we tried to find out which teaching opportunities occur within a role play activity that could be considered valuable for the improvement of mathematical thinking activity. Furthermore, we tried to investigate in detail if mathematics-bound semiotic activity can be triggered within the play context by asking children if they were sure about their mathematical actions, and about the meanings and symbols they used. These queries required explanations and justifications from the children that prompted them to reflect on the meanings of their symbols (notations, words). In order to find answers to these research questions, we analysed eight video-taped sessions (with an average duration of 27 minutes) of role play-activity of small groups of children in a ‘shoeshop-corner’ at school. It turned out that many mathematical teaching opportunities occur and that, if the teacher manages to make use of them, children can explicitly reflect on the relation between symbols and meanings within the play activity. Hence, I draw the cautious conclusion, that play activity can be a teaching/learning situation for the enhancement of mathematical thinking in children, provided that the teacher is able to seize on the teaching opportunities in an adequate way. To what extent this approach also leads to lasting learning results in all pupils is an issue for further study.