Edward Cocker (1631–1676) was an engraver, a skillful calligrapher, and a teacher of writing and arithmetic. He made much of his living embellishing copybooks with his calligraphy. *Cocker’s Arithmetick* was published posthumously by John Hawkins in two volumes: the first, titled *Arithmetick,* appeared in 1677; and the second, *Decimal Arithmetick* (of which the title page is shown below), in 1685. This work became the most popular arithmetic book in England, appearing in 130 editions over a period of 100 years. It is known that Benjamin Franklin and Samuel Johnson owned copies.

During his tenure as editor of *Cocker’s Arithmetick,* Hawkins continually revised the book, adding, for instance, more and more algebra extracted from the text of John Kersey (*c.* 1616–1690). Kersey’s *Mathematical Art, commonly called Algebra* appeared in two volumes (1673, 1674) and became the standard authority in algebra. *Cocker’s Arithmetick* was considered so authoritative that the phrase, “according to Cocker,” was used in conversation to mean “absolutely correct.” In later years, the true authorship of the *Arithmetick* was questioned by Augustus De Morgan (1806-1871), who believed that the real author was Hawkins himself, who built upon the reputation of Cocker. This theory has been successfully refuted and Cocker remains the known, original author of this influential book.

(This image is provided courtesy of the Beinecke Rare Book and Manuscript Library, Yale University. You may use it in your classroom; all other uses require permission from the Beinecke Library. The Mathematical Association of America is pleased to cooperate with the Beinecke Library and Yale University to make this image available to a larger audience.)