In this article, I describe a research/teaching experience I undertook with a class of 5-year-old children in Malta. The topic was subtraction on the number line. I interpret the teaching/learning process through a semiotic perspective. In particular, I highlight the role played by the gesture of forming 'frog jumps' on the number line. I discuss how this gesture appeared to enable the children to shift from the immediate, concrete context to the domain of mathematics. I suggest that the use of the gesture may have been particularly helpful to the children in this class, many of whom were second-language learners.