"Mathematics is generally perceived by students as one of the most difficult school subjects, which is not useful at all in everyday life. For many years there has been social approval for not being good in maths. Therefore, the goal of the Added Value project was to change the approach to teaching mathematics in Polish and European schools. We wanted to show students the practical application of mathematics and set it in the context of everyday life, but above all help students believe that they can learn maths and that it is worth doing.The research carried out as part of the program (in-depth interviews with teachers, desk research etc.) shows that problems with teaching maths are a common experience of various European countries. Often teachers, due to overloaded program or lack of time, limit themselves to theoretical knowledge and imitative exercises instead of teaching how to use maths to solve real-life problems in a creative way. Despite the fact that the core curricula emphasize reasoning, argumentation and problem solving strategies, in practice lessons are often limited to duplication of patterns. Excessive focus on basic skills suppresses curiosity and creativity in students. You can also see the mechanism of dividing students into so-called ""mathematicians"" and ""humanists"", the latter - having once obtained this label feel free from a further being good in mathematics.That is why the School with Class Foundation together with partners from Spain (Asociación Smilemundo), the Netherlands (NHL Stenden) and Ireland (Universal Learning Systems), developed easy-to-use and universal tools that help teachers in conducting lessons that show the practical application of mathematics in everyday life. The materials are based on the design thinking method and show students that maths is an important element of the world around us. They emphasize the role of independent planning and cooperation of students and promote the use of many different soft skills and competences. They show the interpenetration of various fields of knowledge and encourage to strengthen cooperation between teachers. All materials have a common motto “Mathematics is everywhere”! They consist of:• A mathematical toolbox: a set of 8 ready-to-use ideas for interdisciplinary classes with an explanation of the methodology and pedagogical approach (each idea includes ready-made work cards for students and guidelines for teachers, all developed according to one coherent methodology) and open forms for creating own challenges based on program methodology. The toolbox is supplemented with films showing in practice the work of the design thinking method.• a set of interactive mathematical posters.All these materials are available on the easy-to-use website in four languages.The materials developed within the project were extensively tested in schools. 264 schools from four partner countries (261 from Poland and one from the Netherlands, Spain and Ireland) got involved in the tests. 195 teachers were involved (including 191 from Poland). Challenges have been completed a total of 442 times (438 in Poland, 2 in the Netherlands, 1 each in Spain and Ireland). 5296 students took part in the classes (including 5228 from Poland).Tests and evaluation show that the goal of showing the usefulness of mathematics in everyday life has been achieved. While solving real problems students saw maths is necessary in many areas of an adult life. The materials also effectively help change the students' negative attitude towards mathematics to genuine commitment and engagement. They give students the opportunity to make their own decisions and take responsibility. Thanks to the classed based on Added Value scenarios students could also learn self-planning. Working with the design thinking method encouraged students to test different ideas and showed that one can make a mistake for which they will not be punished. The lessons involved all students, including the weaker ones. The materials also supported classroom integration and enabled students to get to know each other better. Teacher confidence in students has also increased. The materials supported interdisciplinary learning and teacher collaboration. By extending the project to other subjects, students practiced many skills at the same time.The materials and the developed approach are and will be further promoted by project partners among schools and local authorities. The use of the proposed scenarios on a wider scale, i.e. the introduction of an interdisciplinary and problem-based approach to the acquisition of knowledge, skills and social competences by students would involve needed changes in the curriculum, a certain reorganization of student styles, but - as our research has shown - it is also possible in the current Polish reality and European schools."