PREFACE

Rational Arithmetic is intended for use in business colleges, and in commercial high schools, by pupils who have completed the equivalent of the eighth or ninth grade in the public school system.

While deficiencies of early training may be remedied by its use, it is not intended as a textbook for those who are approaching the subject for the first time. Neither is it intended to take the place of any of the many excellent works now in use in the grades for the purpose of developing a general understanding of mathematical principles. Such books, while they have satisfactorily discharged this function, have failed to develop the accuracy and facility so vitally essential in commercial calculations.

Other commercial arithmetics have tried to overcome this weakness by following similar plans of instruction in abridged form. Rational Arithmetic follows a very different plan. It is purely a vocational work and therefore places greater emphasis on the "how" than the "why." It is a reference book of commercial operations, rather than a method of presentation, and should be so used.

Part One is a collection of practice exercises arranged along the lines of the generally accepted order of presentation. Part Two contains illustrated solutions covering the entire range of commercial arithmetic as generally understood. The methods used are those of business. The explanations are expressed in language which may be understood easily, rather than in the more scholarly language usually employed.

References throughout the book are by paragraph numbers, which will allow the pupil to ascertain for himself the best method of solving any desired problem.

The aim has been to produce a book so elastic that the teacher may arrange a course of study to suit himself. The author has found it advisable, however, to start pupils with the subject of balancing accounts which arouses their interest and gives them something new and practical.

Drill on decimals should immediately follow this, for the purpose of developing accuracy in locating the decimal point. The advisability of work on the subject of fractions depends entirely upon the attainments of the individual pupil. The writer has found that fully 75 per cent of his pupils are greatly benefited by taking up this subject before beginning the strictly commercial work which commences with the subject of aliquot parts.

It is suggested that the problems in addition at the beginning of Part One be used as drill problems throughout the ' ཏཾ ། ། །ཊཧཱུྃ

Teachers will not find it necessary to use all the problems provided for each subject. The aim has been to give enough problems to meet any demand that may arise.

No claim is made for originality in any of the methods presented Fiery method that appears in this book may be found, in some form, elsewhere. To give credit to the wongoes from which the author has obtained assistance in The doripily Don of this book would be te name al. the textAapka donspltad by him in an experience of nearly thirty trien pa gaizhmotic tenchar.