Mathematical skills and the capacity to apply them in different contexts are a key competence of every educated individual. However, children’s learning outcomes, their interest, motivation and confidence in acquiring skills in mathematics, in learning continuously and relating their knowledge to the outside world remain not satisfactory, despite curricula reforms towards more competence-based education in many European countries. Thus, innovative and creative approaches are indispensible to make the learning of mathematics more active, inquiry-based and interesting, in particular for girls, low achievers and students at risk. “Sounding ways into mathematics” makes innovative solutions accessible for teachers, encourages and trains them to apply these in at least 28 schools in 4 old member states, 2 new member states and Switzerland. The 3-year project provides national teacher training institutions with a tested curriculum dealing with interdisciplinary teaching and learning mathematics with music and sound. It bridges the existing gap between the rapidly advancing science and the traditional school practice. It introduces common teaching principles and a broad portfolio of tools improving children’s learning outcomes, with a high transferability across Europe. It reaches out to school leaders, initial teacher training institutions, the teaching community, European networks, policy makers, parents and students from primary to secondary level. The open resource portfolio is established in collaboration with teachers and school classes who are encouraged to engage in direct exchange. The partnership ensures teachers' continuous professional development and on-going support in terms of know-how, master trainers and networking.