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Mathematical Treasure: Dilworth's Schoolmaster's Assistant

Author(s): 
Frank J. Swetz (The Pennsylvania State University)

This is the title page of The Schoolmaster’s Assistant. The English cleric Thomas Dilworth (d. 1780), whose portrait appears opposite the title page, wrote this most popular English arithmetic. This is the title page of the first American edition, which was published in 1773 and was a copy of the seventeenth English edition.

Fifty-seven American editions and revisions would be published up to 1832. In 1803, the title would be changed to The Federal Calculator, denoting America’s new status as an independent nation. The original title designated the book’s intent as a teacher’s reference. At this period of history students did not have their own textbooks but rather took dictation from their teacher, who possessed the sole text in the classroom. They copied mathematics material into their “cipher books.” It is known that this book was one of the few studied by Abraham Lincoln as a boy.

The frontispiece provides another portrait of Reverend Dilworth.

The Table of Contents supplies a listing of the topics covered in this book.


Near the start of the book we find "On the Education of Youth,” a sermon to parents (above).

Instruction begins on pages 2-3, above, with “On Notation,” whereby students learn to read and write numbers.


Here at the end of the book (page 180) is found a collection of additional exercises, “A Short Collection of Pleasant and Diverting Questions.” Readers may try their hands at these “pleasant” questions.

The images above were obtained from the Pennsylvania State Library, Harrisburg, Pennsylvania. Dr. Iren Snavely, Curator of Rare Books and Manuscripts, was particularly helpful in securing these images.

More early American arithmetic texts in Convergence:

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Dilworth's Schoolmaster's Assistant," Convergence (May 2015)