David Tejido Sáez has a Physics degree from the University of Cantabria, and he works as teacher in San José - Niño Jesús of Reinosa since 2006. In 2014 he participated in the course «Teachers for Change and Innovation», where the experiences seen in other centers located in the spearhead of the methodological change, led him to carry out in his school similar practices based mainly on learning for projects. Since then, as Head of the Science Department, he has motivated and walked with his colleagues towards the implementation of new methodologies and the design of STEM activities. He has promoted several ApS in the Campoo region, and has exhibited in the SIMO (Madrid-IFEMA) with his partner Daniel Rucandio, the mathematical project «Holográmate», that combines Mathematics with Physics and TICs. In addition, both have participated in the STEMforYouth project of the University of Cantabria where they presented an engineering activity called «Floating Nest» with students from the 1st year of ESO, consisting of the design of a floating nest for the Great Crested Grebe. This project became real in the Ebro reservoir, and it has attracted the interest of numerous people linked to education and the environment, and with it, and thanks to the STEMforYouth team, they were able to show it in different national and international events. It is part of the OPENSTEAM Group, which is a research Group focused on teaching and learning of Maths through STEAM (Science, Technology, Engineering, Arts and Mathematics) disciplines. His main task within the group is to train other teachers for the implementation and good development of STEAM projects.