Building knowledge of features of learning mathematics by analyzing videos

In this paper, we approach the development of knowledge of features of the learning of mathematics, by three prospective primary teachers through the analysis of a video where a primary teacher teaches geometry to her pupils. We show how the discussion of the video gives to the three prospective primary teachers the opportunity of professionally noticing pupils' learning, implementing what they learnt in previous courses and creating the possibility to generate new knowledge when they try to understand the pupils.