IN THE early 1950s the mathematicians at the university level began justifiably to criticize the mathematical preparation of high school students for university study. Partly because of this criticism, a number of reform movements arose, of which those of the University of Illinois Committee on School Mathematics, the Commission on Mathematics of the College Entrance Examination Board, and the School Mathematics Study Group were most notable. The activities of these reform groups brought about a great improvement of the mathematics curriculum, though maintaining the traditional separation of mathematics into yearly units of study, especially for algebra and geometry. Included in these programs were quite a few topics not found in the pre-1950 era, such as the structure of the several number systems, the early introduction of the function concept, and a more rigorous presentation of Euclidean synthetic geometry. Likewise, the notions of sets and set operations were used to the advantage of better understanding.