PLAINFIELD ACADEMY, APRIL 20, 180%.. I MAKE use of DABOLI.'s SCHOOLMASTER'S ASSISTANT, in teaching common Arithmetic, and think it the best calculated for that purpose of any which has fallen within my observation. JOHN ADAMS, Rector of Plainfield Academy. [Now Principal of Phillips' Academy, Andover, Mass.) BILLERICA ACADEMY, (Mass.) dec. 10, 1807. HAVING examined Mr. DaBoll's System of Arithmetic, I am pleased with the judgment displayed in his method, and the perspicuity of his explanations, and thinking it as easy and comprehensive a system as any with which I am acquainted, can cheerfully recommend it to the patronage of Instructors. SAMUEL WHITING, Teacher of Mathematics. FROM MR. KENNEDY, TEACHER OF MATHEMATICS. 1 BECAME acquainted with DABOLL'S SCHOOLMASTER'S ASSISTANT, in the year 1802, and on examining it attentively, gave it my decided preference to any other system extant, and immediately adopted it for the pupils under my charge ; and since that time have used it exclusively in elementary tuition, to the great adrantage and improvement of the student, as well as the ease and assistance of the Preceptor. I also deem it equally wellcalculated for the benefit of individuals in private instruction ; and think it my duty to give the labour and ingenuity of the author the tribute of my hearty approval and recoinmendation. . ROGER KENNEDY. New-York, March 20, 1811. THE design of this work is to furnish the schools of the United States with a methodical and comprehensive system of Practical Arithmetic, in which I have endeavoured, through the whole, to have the rules as concise and familiar, as the nature of the sylject will permit. During the long period which I have devoted to the instruction of youth in Aritumctic, I have made use of various systems which have just claims to scientific merit; but the authors appear to have been deficient in an important point the practical teacher's experience. They have been too spacing of examplen, Cspecially in the last rudiments; in consequence of which, the young pupil is hurried through the ground rules too fast for his capacity. This olijcction I have endeavoured to obviate in the flowing treatise. In teaching the first rules, I have found it best to en. courage the attention of scholars by a variety of easy and familiar questions, which might serve to strengthen their minds as their studies grow more arduous. The rules are arranged in such order as to introduce the most sinple and necessary parts, previous to those which are more abstruse and diflicult. To enter into a detail of the whole work would be te. dious; I shall therefore notice only a few particulars, and refer the reader to the contents. · Although the Federal Coin is purely decimal, it is so nearly allied to whole numbers, and so absolutely necessary to be understood by every one, that I have introrucell it immedliately after addition of whole numbers, and also shown how to find the value of goods therein immediately after simple multiplication; whicls may be of great advantage to many, who perhaps will not have an opportunity of learning fractions. In the arrangement of fractions, I have taken an entire new methodl, the advantages and facility of which will suficiently apologize for its not being aceording to other systems. As decimal fractions may be learned much easier than vulgar, and are more simple, useful, and neces. sary, and soonest wanted in more useful branches of Arithmetic, they ought to be learned first, and Kulgar, Fractions omitted, until further progress in the science shall make them necessary. It may be well to obtain a general idea of them, and to attend to two or three easy problems therein : after which, the scholar may learn decimals, which will be necessary in the reduction of currencies, computing interst, and many other branches. Besides, to obtain a thorough knowledge of Vulgar Fractions, is generally a task: too hard for young scholars who have made no further progress in Arithmetic than Reduction, and often discourages then... I have therefore placed a few problems in Fractions, according to the method above hinted ; and after going through the principal mercantile rules, have treated upon Vulgar Fractions at large, the scholar being now capable of going through them with advantage and ease. In Simple Interest, iu Federal Money, I have given several new and concise rules; some of which are particularly designed for the use of the compting-house. The Appendix contains a variety of rules for casting Interest, Rebate, &c. together with a number of the inost easy and useful probleins, for measuring superficies and solids, examples of forms commonly used in transacting business, useful tables, &c, which are designed as aids in the common business of life, Perfect accuracy, in a work of this nature, can hardly be expected ; errors of the press, or perhaps of the au. thor, may have escaped correction. If any such are pointed out, it will be considered as a mark of friendship and fayor, by The public's most humble NATHAN DĄBOLL. Page. Alligation i i i . . . Coins of the United States, Weights of Division of Wliole Numbers . . Evolution, or Extraction of Roots Fractions, Vulgar and Decimal • by Decimals . . Loss and Gain .. on Page. Questions for Exercisei . ii. 1209 Reduction . 63 of Currencies, do. of Coin :: 89, 93 Rule of Three Direct, do. Inverse . . 100, 108 Double . . . . . . . : 148 several United States, also Canada and No. for finding the contents of Superfices & Solids 220 or to reduce the currencies of the different States, to Federal Money"... en sum for months and days ; Subtraction, Simple . Compound .. . : Table, Numeration and Pence ; Adition, Subtraction, and Multiplication United States, with Sterling, &c. ; 236 other currencies . . . .. French, gold coins, in dollars, cents, & mills: O Hendred or Minions LO O Tens of Millions. 233 237 114 238 |