Pupils and teachers of 3 Primary Schools (Greece and Belgium) collaborate on the project “STEAM Challenges” (October 2019- June 2020). Pupils are going to be involved in experiential STEAM based activities in order to acquire experimental skills, to explore the S.T.E. (A.) M. sector(s), to learn about computational thinking, to learn to code and to acquire 21st-century skills such as collaboration, communication and critical thinking. The project is framed by a storytelling. Each challenge is an episode (interrelated episodes). Students had to help the main character, Gren, overcome the difficulty he was facing in each episode. The project is based on sociocultural learning theories through cooperative activities, communication and pupils’ decision making through democratic processes.