WITHIN the past quarter-century there has been much controversy over what should be included in a course in commercial mathematics. In 1934 a large group of office managers rated such a course second among practical commercial subjects.' Yet in many places the course in commercial mathematics has fallen into disrepute, with the result that the schools offering it are decreasing in number. The first term of a course in commercial mathematics usually consists in repeating the elementary-school work in addition, subtraction, multiplication, division, and common and decimal fractions. Such a repetition seldom challenges the pupil's interest and often is a waste of time.2 The content of the course in commercial mathematics as now taught in most schools has no scientific reason for existence, since it is not known, as yet, how closely this subject matter satisfies the needs of the business world. Moreover, thinkers in the field suggest that, because of the prevalence of calculating machines in business offices, the informational aim should be given greater recognition than the operational. Furthermore, businessmen are justly annoyed by the school's failure to teach a mathematics vocabulary, since the chief difficulty of the business apprentice seems to be his lack of understanding of language concepts behind problem-solving. The pupil entering business with a precise and adequate terminology, thoroughly understood, would find his apprenticeship period appreciably