In this study we attempted to highlight the pedagogical role of activities to familiarize pre-schoolers with the measurement processes of container capacity. The sample of the study consisted of 20 subjects aged five-six, all coming from two Greek state kindergartens of the same area, bearing the same middle socioeconomic background. The research was conducted in three phases (pre-test, teaching intervention and post-test). During the pre-test and post-test, the subjects' reasoning was recorded through personal interviews, each of which lasted 15-20 minutes. In the pre-test we attempted to check whether the children could carry out direct (using just the containers) and indirect (using a common measure) comparisons between container capacity. In the teaching intervention we proposed activities to small groups of children which aimed at creating the kinds of frameworks that would allow them to compare the capacity of containers and to elaborate on the concept of capacity. Finally, in the post-test, we evaluated the influence of the teaching intervention on the improvement of the children's ability to handle issues related to the comparison of the capacity of containers, as well as to the measurement of capacity. Our findings highlight the important role of the communication framework in teaching, as it reinforces the pupils' autonomy and contributes to the acquisition of new knowledge. (Contains 2 tables.)