"KeyMath" aims at innovations of mathematics education on the European level in four target areas. The project develops, tests, evaluates, disseminates and exploits(1) strategies for pupils’ active, exploratory, self-regulated, autonomous, communicative and collaborative learning to develop key competences (mathematical competence, communication in the mother tongue, digital competence, learning to learn, social competences, sense of initiative), (2) teaching methods that effectively support the development of key competences in mathematics education according to the "European Reference Framework of Key Competences",(3) assessment methods that correspond to the competence-based approach and that enable teachers to diagnose pupils’ key competences, to identify difficulties in this area and to support pupils with these difficulties in primary and secondary school,(4) strategies for integrating the European dimension in teaching and learning mathematics."KeyMath" operates in four fields of activity:(1) The partners use the power of in-service teacher education for initiating innovations in mathematics education. Networks of teachers are intensively involved in the project. They are made familiar with didactic concepts for teaching, learning and assessment to support pupils’ key competences.(2) Initial teacher education is the basis of mathematics education in the future. So the partners implement the didactical concepts in initial teacher education.(3) Dissemination and exploitation strategies with publications of didactic concepts and concrete teaching/learning/assessment material in Bulgarian, Czech, English, German, Greek and Norwegian contribute to the improvement of mathematics education on the large scale in Europe.(4) To enhance the impact on the level of educational systems, project results are exploited among decision-makers in politics, administration and educational practice as well as in the scientific community of mathematics education.