In this paper we present a STEM education initiative. This initiative involves an improved learning approach by means of the implementation of collaborative learning techniques. The proposed approach promotes computational thinking skills in a group manner to improve the learning of geometry. Two case studies were performed with primary school children in the fourth grade at the Comfacor School (Montería-Colombia). The aim of these studies was to analyse the effects of the improved approach in three aspects: the children' motivation, satisfaction and performance. The obtained results provide evidence that the learning of geometry was enhanced thanks to the proposed approach implemented based on a computational thinking strategy.