Mathematical Treasure: The Arithmeticae practicae of Gemma Frisius

Gemma Frisius (1508–1555) was a Dutch mathematician and medical doctor who served as Professor of Medicine and Mathematics at the University of Louvain. In 1540, he published his arithmetic textbook, Arithmeticae practicae. The title page of a 1556 edition is shown below.

On page 18 of this work, Frisius gave a table of the basic multiplication facts up to 9 x 9. Note that the table was constructed to emphasize the commutative property of multiplication, and that the main diagonal is labeled as square numbers, or “Quadrati numeri”:

The squares and cubes of the numbers 1-9 are shown on page 89:

Here on page 104 of his Arithmeticae practicae, Frisius discussed “Regula Falsi,” or the Rule of False Position:

The images above are supplied through the courtesy of the United States Library of Congress and may be viewed at its website.

Index to Mathematical Treasures