The key to The tutor's guide [electronic resource] : or, the arithmeticians repository. Containing the solutions of the questions, &c. in The tutor's guide. With the references as they stand in the second edition. To which is added (where necessary) some useful rules, &c. As those for the attaining a thorough Knowledge of Circulating Numbers. Likewise an appendix, Shewing the Combination of Quantities; the different Ways they may be varied; with the Method of filling the Magic Squares, &c. The whole being principally designed for the Ease of School-Masters, and, with the Guide, furnishes a more Complete and Extensive System of Arithmetic, than any extant; and will enable all those who are acquainted with the first Principles, to attain a competent Knowledge of the several Rules, with Ease and Precision. The secon edition, corrected. By Charles Vyse, Teacher of the Mathematics, and Master of Westham-Abbey Boarding-School.