MATHEMATICAL TEXT-BOOKS BY GEORGE A. WENTWORTH Mental Arithmetic Elementary Arithmetic Practical Arithmetic Primary Arithmetic (Wentworth and Reed) Grammar School Arithmetic Advanced Arithmetic First Steps in Algebra New School Algebra School Algebra Elements of Algebra (Revised Edition) Shorter Course in Algebra Complete Algebra Higher Algebra College Algebra (Revised Edition) First Steps in Geometry (Wentworth and Hill) Plane Geometry (Revised) Solid Geometry (Revised) Plane and Solid Geometry (Revised) Syllabus of Geometry Geometrical Exercises Analytic Geometry Plane and Solid Geometry and Plane Trigonometry (Second Revised Edition) Plane Trigonometry (Second Revised Edition) Plane Trigonometry and Tables (Second Revised Edition) Plane and Spherical Trigonometry (Second Revised Edition) Plane and Spherical Trigonometry and Tables (Second Revised Edition) Plane and Spherical Trigonometry, Surveying, and Navigation (Second Revised Edition) Surveying and Tables (Second Revised Edition) Plane Trigonometry, Surveying, and Tables (Second Revised Edition) Plane and Spherical Trigonometry, Surveying, and Tables (Second Revised Edition) Logarithms, Metric Measures, etc. A PRACTICAL ARITHMETIC BY G. A. WENTWORTH AUTHOR OF A SERIES OF TEXT-BOOKS IN MATHEMATICS GINN & COMPANY BOSTON .NEW YORK • CHICAGO LONDON HARVARD COLLEGE LIDHARY GINN & CO. Entered, according to Act of Congress, in the year 1893, by in the Office of the Librarian of Congress, at Washington Copyright, 1897, by G. A. WENTWORTH ALL RIGHTS RESERVED 314.5 The Athenæum Press PREFACE. PUPILS can be trained to logical habits of mind and stimulated to a good degree of intellectual energy by solving problems suited to their capacities. By this course they acquire practical mastery over the everyday problems of common life as well as gain the very best mental discipline. The shortest and best way of learning Arithmetic is by solving problems. The rules which this book contains are not intended to be committed to memory, but to help the pupil to neat and intelligent methods. The rules follow explanations of processes, and no rule should be considered until the process which it summarizes is thoroughly understood. Dependence upon set rules and formulas is the worst possible mental slavery. This The examples are in the main new, and contain a great deal of accurate and valuable information of the latest date, while they are well-graded and progressive. Arithmetic and the author's Elementary Arithmetic are intended for a two-book course sufficiently comprehensive to cover all the work that should be required of pupils in general. The Appendix contains subjects of value only for pupils in the States named, and other subjects of little practical value but convenient for reference. |