THE

FEDERAL CALCULATOR.

OR,

A CONCISE SYSTEM

OF

PRACTICAL ARITHMETICK;

CONTAINING

ALL THE RULES NECESSARY FOR TRANSACTING THE
COMMON BUSINESS OF LIFE.

TOGETHER WITH

QUESTIONS FOR EXAMINATION,

UNDER EACH OF THE RULES;

INTENDED FOR

THE USE OF SCHOOLS, AND YOUNG MEN

WHO MAY BE DESIROUS OF OBTAINING FURTHER KNOWLEDGE
OF THIS SCIENCE.

UNIVERSITY

LIBRARY 04-2773

Western District of Virginia, to wit:

BE IT REMEMBERED, that on this twenty-eighth day of July, in the year of our Lord one thousand eight hundred and twenty-eight, and in the fifty-third year of the Independence of the United States of America, WILLIAM SLOCOMB of the said District, has deposited in my office the title of a book, the right whereof he claims as author and proprietor, in the words following, to wit:

"The Federal Calculator, or a concise system of Practical Arith"metick; containing all the rules necessary for transacting the com"mon business of life; together with questions for examination, under "each of the rules, intended for the use of schools, and young men "who may be desirous of obtaining further knowledge of this science. "To which is added, a short system of Book-keeping. By William "Slocomb."

In conformity to an Act of the Congress of the United States of America, intitled, "An Act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies, during the times therein mentioned;" and also, to an Act entitled, "an Act supplementary to an Act, entitled, an Act for the encouragement of learning, by securing the copies of maps, charts and books, to the authors and proprietors of such copies, during the times therein mentioned, and extending the benefits thereof to the arts of designing, engraving, and etching historical and other prints.

JASPER YEATES DODDRIDGE, Clerk of the Western District of Virginia.

PREFACE.

IN offering the following pages to the publick, the author feels it incumbent on him to state some of the reasons, which have induced him to add another, to the numerous treatises on Arithmetick now in use.

Having been engaged, for more than twenty years, in the business of teaching, I have found it of great importance, that every thing relating to the science of Arithmetick, should be presented to the mind of the young learner, in as simple and concise a manner as possible, unincumbered with terms not readily understood by them; and that the principles embraced under each rule, should as far as practicable, be at once presented to the mind in a plain, familiar manner, instead of being divided into a number of Cases, tending rather to confuse than enlarge the understanding. For this purpose many of the rules found in this work, were written for the benefit of my own pupils, without the most distant idea, at the time, of their ever being published. The questions also which are inserted at the close of each rule, are such as I have long been in the practice of asking my scholars, or requiring them to put to each other, in a class formed for the purpose, and from which much good has resulted, in rendering the principles contained in the rules, familiar to the mind. These ques tions should be repeated, till the learner is able to answer them readily, not only in the natural order in which they stand, but also when put promiscuously, embracing several rules in the same lesson.

We find in all the arithmeticks now in use, a large proportion of the questions stated in English Money, and consequently much of the time of the pupil is wasted, without adding scarcely any thing to his stock of useful knowledge. The time has arrived, when accounts in our country, should no longer be kept in that currency. In this work, therefore, the whole of the calculations are in Federal Money, except in the Compound Rules where English Money is introduced with the weights and measures, and in a few other cases where it seemed necessary, Practice, &c.

as in

The several rules are arranged in that order in which they seemed best calculated to reflect light on each other, and so as not to require a large and separate explanation. The previous rules open the way to those which follow in so plain and easy a manner, that the pupil may proceed without much obstruction, and gradually acquire a connected and enlarged view of the whole science.

In the whole of this work, two things have been kept constantly in view, viz: to furnish our schools with a plain and easy system of arithmetick, unincumbered by useless questions, or such as would have a tendency to puzzle, rather than improve the learner: and also, to put into the hands of those young men, who, from their peculiar situation in a new country, could not, at the proper age, enjoy the advantages of a common school education, the means of acquiring, without the aid of a teacher, such a knowledge of this useful science, as to be able, without embarrassment, to transact the common business of life. For the purpose of enabling them to do this with greater facility, an explanation of the first example under each rule, will be found generally through the work.

If I might be allowed to invite the attention of the reader to any particular portion of this treatise, I would men

fion the method of calculating Interest, the rule of Practice, the Illustration of the reason and nature of the Roots, the Application under the rules generally, and the Promiseuous Questions at the close of the work. A large number of these is inserted as a kind of supplement to the foregoing rules, for the purpose of affording the learner an opportunity for exercising his judgment, in the method of operation, without having any particular rule before him. Every teacher who has had even but little practice, must have seen the great importance of such a course.

The work is, with diffidence submitted to the publick. That it is perfect, is not pretended: but it is hoped but few errors will be found in it, as every question has been carefully wrought, by myself, and also by one of my most accurate pupils. Should it help to facilitate the progress of youth in acquiring a knowledge of Arithmetick, my object is attained. I have only to request that it may not be condemned unexamined. WM. SLOCOMB.

A WORD OF ADVICE TO LEARNERS.

Never take your slate in hand till you understand the rule by which your question is to be wrought; nor call on your teacher for assistance till you have made a thorough trial by yourself, remembering that the most useful knowledge is that which is gained by your own study and reflection.

Never leave a rule, and the operations under it, till you thoroughly understand it; and not only see that the answers are produced, but also know the reasons why they are.

Remember that idleness and sloth are great enemies to improvement, therefore drive them far from you. The season of youth will soon pass, and with it the best, and usually the only opportunity for preparing yourself for a useful and respectable station in society.