The early publication history of the very short Breviarium of Guillaume Budé's De asse et partibus eius is analysed and clarified, and the earliest versions are dated to c. 1520. Though short, it was an influential little work, and in particular its links with Cuthbert Tunstall's De arte supputandi are explored. It is argued that Bude himself was the author of the Brevianum, and that it may have a relevance to the Budé/Porzio controversy about the 'sestertius' and 'sestertium'.