The study aims to describe variation in the expression of students’ mathematical ability and the various ways in which their mathematical aptitude is acknowledged and supported by their teachers, parents and peers in a Swedish context. Ability is defined as a complex of various abilities each of which may be more or less pronounced in a given individual. The study is based on ten case studies of highly able students (ages 6-19). Six of the studies are longitudinal, ranging from three to six years. In order to validate the results of the case studies, two survey studies were carried out involving 180 teachers (preschool to Grade 9 in Swedish compulsory school) and 284 mathematics developers from 229 Swedish municipalities. The survey studies raised questions concerning the teachers’ personal experience of identifying and supporting highly able students, the nature of their everyday teaching, and the support given to able students. The results show that mathematical abilities can take many different forms and there is great need for pedagogical support for this group of students. Since extra resources are rarely available for the benefit of nurturing talent and since there are, as yet, no Swedish national or local policy documents that specifically address the support of talent in students, teachers are on their own in figuring out how to best help able students develop mathematically. The study points to the importance of the social norms that influence the interaction between teacher and student(s): everyday social norms as well as socio-mathematical norms, i.e. norms specific to the subject of mathematics. The latter place considerable demands on the teachers’ mathematical knowledge and competence. The benefits of early interventions, of supportive teaching environments, and of providing the students with challenging tasks and questions are also discussed.