This textbook is part of a series designed to give an elementary school child all the arithmetical power necessary to cope with the situations of common everyday life. This book covers fundamental elements of arithmetical manipulation and thought. Thus, a child who goes no farther than the fourth or fifth grade will be so familiar with essentials that he can readily learn more arithmetic by himself. The topics, problems, and processes are representative of the arithmetical facts, power, and skill that will be most useful to the average citizen. The methods of treating them have been garnered from the most successful teaching practice.