The Hauksbók (Book of Haukr) is one of the few medieval Norse manuscripts of which the author is known. His name was Haukr Erlendsson (d. 1334), and as long back as it is possible to trace the manuscript it has been called the Hauksbók after its author. It was partly written by Haukr himself, partly by assistants. The book contains versions, sometimes the only extant versions, of many Old Icelandic texts, such as the Landnámabók, the Fóstbrœðra saga, the Eiríks saga rauða, the Hervarar saga and the Völuspá.
Palaeographical evidence allowed Stefán Karlsson to date the manuscript to between 1302 and 1310 ("Aldur Hauksbókar", 'Fróðskaparrit', 13 (1964), 114–21).
The book contains a section on mathematics of ca. 6-7 A4 pages, called Algorismus. This is the oldest text on mathematics in a Scandinavian language. It is probably a translation from Latin into Old Norse of some pages included in more ancient books such as Carmen de Algorismo by De Villa Dei of 1200, Liber Abaci by Fibonacci of 1202, and Algorismus Vulgaris by De Sacrobosco of 1230.