This textbook presents an arithmetic course that seeks to adapt the subject matter to the experiences, interests, and immediate needs of children, and to provide means for a mastery of the formal phases of arithmetic through more scientifically organized drills. This series consists of three books: Primary (ED622333), Intermediate (ED622334), and Advanced. The Primary book contains the work suggested for the second, third, and fourth grades; the Intermediate, the work for the fifth and sixth grades; and the Advanced, the work for the seventh and eighth grades. The text uses only problems that deal with the experiences of children. They deal with their chief occupation -- play, with their constructive activities, with phases of the home and the local community life with which they come into direct contact.