The rationale for teaching mathematics to prospective elementary school teachers is quite straightforward. A teacher must obviously have some knowledge of the discipline's subject matter in order to insure adequate learning on the part of instructed students. This is normally accomplished by requiring the elementary education major to take a prescribed number of courses dealing with concepts deemed relevant to the elementary mathematics curriculum. The problem with this procedure is that the college textbook writer must himself arbitrarily decide which concepts are relevant and which are not. The purpose of the present article is to propose a procedure for teaching mathematics to propective teachers that avoids much of this arbitrariness.