Teachers all over the world are teaching Mathematics in classrooms that may have students grouped by ability. Often the decision to group or not to group is made arbitrarily or because this is the way classes have always been arranged. This book will provide a valuable insight into the impact ability grouping has on the learning environments of Mathematics classrooms. The reader will gain insights into how different stakeholders in the schooling process relate to the concept of academic segregation. Information will be revealed on students? preferred learning environment and the way their attitude to mathematics can be shaped by the way their classes are grouped. Principals, heads of departments, teachers at all levels and academics who are interested in the study of learning environments may be caused to think about and even reconsider their position on the place of ability grouping in the education process.