systems. As decimal fractions may be learned much easier than vulgar, and are more simple, useful, and necessary, and soonest wanted in more useful branches of Arithmetic, they ought to be learned first, and Vulgar 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 proulems 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 them. 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, in 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 most easy and useful problems, 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 he expected; errors of the press, or perhaps of the author, may have escaped correction. If any such are pointed out, it will be considered as a mark of friendship and favor, by The public's most humble and obedient Servant NATHAN DABOLL. 89, 93 — of Currencies, . do. of Coin Rules, for reducing the different currencies of the 96, 97 Rebate, A short method of finding the, of any giv- en sum for months and days 217 showing the amount of 17. or 1 dollar, at 5 & 6 per cent. Compound Interest, for 20 years shewing the amount of 11. annuity, forborne for 31 years or under, at 5 and 6 per cent. showing the present worth of 17. annuity, for 31 yrs. at 5 & 6 per c. Compound Interest of cents, answering to the currencies of the United States, with Sterling, &c. Weights of several pieces of English, Portuguse. & of English & Portuguese gold, do. |