‘ARITHMETICK is a Science by which we come to know what Number of Quantities there are (either real or imaginary) of any kind, contained in another Quantity of the same kind.’

John Ward, *The Young Mathematician’s Guide*, p. 2.

Arithmetic is a subject with which most students will be very familiar. The subject has a wide range from multiplying or dividing large numbers to representing fractions or decimals. One must be aware that calculators are a recent invention in the context of the history of mathematics and before they were readily available mathematicians and school students alike needed other methods to compute difficult calculations by hand. Moreover, there was a need to document mathematical methods in a simple and understandable manner so that they could be studied by budding mathematicians.

One of the most important texts which aimed to disseminate the basics ideas behind these calculations was Cuthbert Tunstall’s work *De arte supputandi libri quatuor*.

Cuthbert Tunstall, *De arte supputandi libri quatuor* (Paris, 1538), title page.

This publication was inherited by Edward Worth from his father John Worth (1648-1688), Dean of St. Patrick’s Cathedral, Dublin, who in turn had inherited it from his father Edward Worth, Church of Ireland Bishop of Killaloe (d. 1669). It is likely that Worth was interested in both the content of the book and the fact that is was published by the renowned sixteenth-century French printing press of the Estienne family.

**Text:** Fionnán Howard