This project is the next step of our ongoing project. But we wanted to make it even more collaborative. It mixes up different subjects such as Biology, Physics, Maths. Indeed, we noticed that our pupils find it difficult to figure out the different levels of organization of elements that surround us. The main aim of this work is to have a better understanding of these elements (molecules, bacterias, Cells, organs etc…), their organization and / or function and the size relationship between them.