The pedagogics of the leisure time center where the signifiers are the group, the experience and the situation, all these would make possibilities for the leisure time teachers to work with mathematics in an untraditional way, to complement the formal mathematics with an informal, everyday mathematics. This way to educate goes together with what the science depicts is missing in the traditional way of educating. The students need to work more with problem solving, creative, colloquial and practical with mathematics, preferably in interaction together. The purpose of the study is to try to get to know how the leisure time center operates to enable the development in mathematics of the students. Which are the activities the leisure time center offers where the students mathematical competence increases through encouragement and challenges. To get material for my analysis I have chosen two methods, observations and interviews, to get a broad and immerse comprehension of the scope of the survey. I have proceeded from the mathematician Alan Bishop and his theories about the six universal mathematical activities. I have also chosen to link my observations and the interviews to the social constructivism, i.e. that the human active construct knowledge in interaction together with others. The result of the survey is that the teachers has a good theoretical competence when it comes to informal mathematics. The presented activities are mostly sport and playing, and the equipment that is offered has to do with sport. These activities are according to Bishop mathematical activities themselves, but to encourage and challenge the students in their mathematical development, it requires mental presence, dedication and curious teachers.