The present study discusses the opportunities that are available to students with high mathematical abilities in school mathematics. Our focus is on teaching mathematically able students (MAS) in heterogeneous mathematics classrooms. Based on individual interviews with teachers, we describe images that teachers hold of mathematically gifted students. By analyzing multiple classroom observations, we characterized the roles that the teachers assign to MAS in the mathematics classroom and found that the teachers use MAS to help them manage the whole-class discussion fluently. At the same time, we found no special mathematical activities that the teachers prepared for MAS in any of the observed lessons. We suggest that mathematics teachers need special preparation for the education of MAS in each and every type of mathematics class.