The Schoolmasters most useful companion, and scholar's best instructor, in the knowledge of arithmetic. [electronic resource] : In two parts. Part I. Containing the first principles of arithmetic, with plain and concise directions to work the rules of addition, subtraction, multiplication, division, reduction, the rule of three, practice, interest, rebate and discount, fellowship or partnership, alligation, progression, vulgar and decimal fractions, extraction and use of the square and cube roots. With a variety of practical questions, to exercise the scholar in all the foregoing rules, each question having the answer inserted, in order to save the master or tutor a great deal of time and labour, and help the scholar forward in his progress in the practical part of arithmetic. Also, rules for performing cross multiplication, with the application to actual practice in measuring carpenters, joiners, paviors, thatchers, and bricklayers work, and the manner of gauging coolers, cisterns, and casks in wine, ale gallons, and malt bushels, both by the pen and sliding rule. Part II. Comprehending a short and simple sketch of book-keeping, by way of common debtor and creditor; by which accompts may be kept with great east and exactness. The whole digested in such a manner as to render it not only useful in almost every branch of life and business, but very entertaining. The fourth edition, corrected, improved, and recommended by several of the most eminent schoolmasters, and expert arithmeticians in the Kingdom. By D. Fenning, Author of The Royal English Dictionary, Young Man's Book of Knowledge, Young Measurer's complete guide, &c.