NEW

COMMERCIAL ARITHMETIC

BY

JOHN H. MOORE

NEW YORK.:. CINCINNATI .:. CHICAGO
AMERICAN BOOK COMPANY

HARVARD
UNIVERSITY
LIBRARY

COPYRIGHT, 1904, BY

L. L. WILLIAMS AND F. E. ROGERS.

ENTERED AT STATIONERS' HALL, LONDON.

MOORE'S COM. AB.

W. P. 6

PREFACE

A commercial arithmetic should be comprehensive in its scope, but should contain no complicated or obsolete subjects. It should furnish abundant material for drills in modern business problems, and, by natural and progressive steps in the methods of developing the subjects presented, should cultivate in the student those qualities of accuracy, rapidity, and self-reliance that will be so valuable to him later.

With these objects in mind this book has been written. It is not intended for beginners, but for students pursuing a commercial course in business and secondary schools. While it may be assumed that these students have previously completed a more elementary arithmetic, yet experience has demonstrated that it is usually necessary for them to review the fundamental operations, and become familiar with the short methods which are applicable to simple calculations, before they can do effective work in commercial arithmetic. The underlying principles of arithmetic are, therefore, briefly reviewed, and many practical counting-room methods having a direct bearing upon them are carefully illustrated and explained.

Great care has been taken to make the methods of developing all the principles natural and businesslike. All of the operations given in connection with the illustrative problems are accompanied with solutions which enable the student to understand the principles involved. The student is taught to understand a process before he is taught to summarize it in a rule. Solutions and rules are omitted in all cases where it is thought the student can prepare them without assistance. The few rules given in the book all follow solutions, and are intended to aid the student to produce intelligent results. In no case are they intended to be committed to memory.

Mental work has received due emphasis throughout the book. Oral exercises of a thoroughly practical nature accompany every subject, and in many cases methods of computation are introduced and developed through a series of oral drills.