Mathematical Treasure: Spanish Practical Arithmetic Based on Pacioli

The Sumario breve d[e] la pratica de la arithmetica d[e] todo el curso del arte mercantiuol bien declarado, el qual se llama maestro de cuento (Suma aritmética) (1515) was written by the 16th century Spanish Catholic priest Juan Andrés. Intended for merchants, this pratica or practica is based heavily on the work of Pacioli.

The use of finger signs and symbols to communicate numbers is still an important skill in trade. At the beginning of his book, Andrés introduced these “finger numerals.”

The multiplication and reduction of common fractions is discussed in the latter part of the text. At the top of this folio, the product of 2/3 and 3/4 is found to be 6/12, which is then reduced to 1/2.

The images above were obtained through the cooperation of the Hispanic Society of America Museum and Library. A facsimile of this book is offered by the publisher Vicent García Editores in cooperation with the Universidad de Salamanca.

Index to Mathematical Treasures