Forster's arithmetick : Explaining the grounds and principles of that art, both in whole numbers and fractions. By such plain, easie and familiar rules and precepts, that any person, of a reasonable capacity, may (in a short time) attain to a competent proficiency therein, without the help of any tutor. By William Forster. - Forster, William, (printed by John Streater, and are to be sold by George Sawbridge, at the Bible on Ludgate-Hill,, 1673)