SLAM is an innovative project aimed at creating and developing devices, exchanging learning practices and materials in the STEM area by way of computational thinking, and highlighting the importance of synergy of all knowledge and skills needed for work in STEM to accomplish good results in that field.Four schools were involved in the project – Croatian, Cypriot, Greek, and Estonian. As the name of our project suggests (SLAM - STEM Learning Activities & Methodology), all partner schools created activities for each of the following: science, technology, engineering, and math. Science was assigned to the Croatian partner, technology to the Estonian partner, engineering to the Cypriot and math to the Greek partner. Each partner has the most experience in their chosen field, so their task was to support and train other partners although from the beginning, all partners had activities covering all the fields. The main participants of the project were students aged 13-15, and the total number of students of all four schools was approximately 250. Every school included a subset of its teachers (28 in total) and school staff, students’ parents, the local community, neighboring schools and scientists. All activities were based on defined project’s objectives: achieving higher levels of cognitive knowledge necessary for active work in STEM, improving basic competencies with emphasis on the STEM field, improving foreign language use, increasing students’ experience in areas needed for further education, raising motivation for the use of ICT in learning and teaching, introducing new teaching methods in daily work to other colleagues, expanding the range of extracurricular activities in schools and making them part of the schools' curriculum. Participants developed and promoted the acquisition of relevant and high-quality skills and competencies.Students' and teachers’ activities were organizing workshops, webinars, holding presentations and meetings, planning and participating in Science Days, visiting science festivals, setting up speeches by scientists, conducting experiments and field research, making scientific devices and tutorials. Students and teachers from Cyprus, Greece and Croatia took part in euroMath and euroScience 2019 as a team. By participating in the project, students developed a sense of accomplishment and success, used new methods of work, expanded their horizons, and gained new friends. Holding project activities increased their motivation for working in the STEM area because they were, through immediate practical work, able to directly see products of their labor. They also gained insight into novel ways of learning, resulting in their greater inclusion in newly formed extracurricular activities. They achieved better results in school because they used new learning methods and raised their cognitive knowledge to a higher level which was shown through the results of the final assessment. They developed basic competencies in STEM area which resulted in taking part in euroMath and euroScience and National biology competition, Math competitions, ICT Competitions, NASA Apps challenge . They also acquired various skills needed for practical work and improved the usage of English language through communication and presentation of their work in LTTA. Teachers increased the quality of their work by applying new methods which will also influence the education of future generations. Concrete results upon the completion of project are the developed STEM KITS - building sets for F1 car, a hologram, a seismograph and a power bank, the production of methodological brochures, tutorials to teach a wider public, a book of students' scientific reports, STEMopoly game.Methods used in the project were research, problem-solving, simulation, games, practical work, fieldwork and discussion for the purpose of gaining new knowledge. Through research, students reached high cognitive levels that will enable conceptual understanding of topics that need to be learned.An important method that students used is computational thinking, consisting of three parts: identifying the problem and its abstract formulations, dividing it into several steps - smaller problems and making a strategic way of solving them. This kind of work enabled students to see more clearly how machines and computers operate and to understand the language of computers better, which is a prerequisite for successful work with advanced technology and for achieving higher levels of cognitive knowledge needed for active work in STEM areas.Long-term benefits include the expansion of the schools’ curriculums with extracurricular activities: 3-D modeling club, Programming club, Lego Mindstorm club, Craftsmanship and invention club, Experiments club, Innovation Lab club, Robotics club, Science club. Teachers become more creative, flexible, open-minded. This reduced the number of reluctant teachers in schools. Schools became more modern, dynamic and cooperative.