This report summarizes the data from a comparative study of grades 2 and 5 mathematics instruction and the use of Developing Mathematical Processes (DMP) in IGE and non-IGE settings. These results are part of a five-phase evaluation of the IGE system of elementary schooling. Use of DMP and reported adoption of IGE were not found to be good indicators of instructional patterns in mathematics. At both grades, the instructional emphasis was on computation, with insufficient time allocated to other important areas of mathematics, in particular problem solving at grade 5. Use of worksheets exclusively was found to be ineffective for increasing achievement. Use of manipulative materials was very effective for increasing achievement for some objectives. (Author)