The arithmetician's guide. [electronic resource] : In two parts. Part I. Containing practical arithmetic, thro' all its several denominations; in Examples wrought at large, and in a plain and easy Manner exhibited, and the Work of Fractions, both Vulgar and Decimal, compleated. Part II. Containing the principles of algebra, in a more plain and intelligible a Manner, than any heretofore extant. Illustrated in the Numerical and Literal Solution of many Examples, both in Simple and Quadratic Equations. Wherein every Process, both by Figures and Letters, are from Rules, so plain, easy, and clear, that Persons of a mean Understanding may comprehend them. By Tho. Crosby, Teacher of the Mathematics, upon Horsely-Down, in Southwark.