It is commonly acknowledged that the process of division, particularly division by numbers of more than one digit, is the most difficult of the four fundamental operations in arithmetic. The complexity of the process easily accounts for its difficulty. This article reports the results of an attempt to reduce the difficulties encountered by pupils in learning the process of The common procedure in teaching division is to teach first what is called division; that is, the pupils are taught to divide by one-digit numbers, writing only the figures in the quotient and performing the necessary multiplication and subtraction mentally. Later they are taught long division, that is, dividing by a number of at least two digits by following a complex system of estimating the first digit in the quotient, multiplying, writing the product, subtracting, annexing to the remainder the next digit from the dividend, and so on. When this teaching procedure is followed, the pupil learning short division is confronted with the difficulty of understanding a new and involved process, which is complicated by the fact that most of the numbers with which the pupil deals are invisible. When he undertakes long division, he must deal with the new difficulties presented by the estimation of the figures in the quotient, and at the same time he must learn to use a new form of solution, which may easily serve to conceal from him, for a time at least, the fact that the process is essentially the same as that with which he is already familiar under the name division. To lessen these difficulties, it has been proposed that only the long-division form of solution be taught, all division, regardless of the number of digits in the divisor, being performed by means of that form. In order to determine the effectiveness of this procedure, two groups of fifth-grade pupils in the University Elementary School of the University of Chicago were