This volume, edited by Johann Sichardt (1499-1552) from an unknown manuscript, contains two of Bede's works, the first on the nature of things, based on the work of Isidore of Seville, and the second on the reckoning of time. Bede, however, disputed Isidore's traditional chronology, which led to him being accused of heresy for putting the date of Christ's birth in the wrong age. The calculations for the date of Easter had extra significance in England in the seventh century, as the Synod of Whitby had declared that the Celtic Church should follow Roman practice rather than its own traditional dating. "Bede's treatment of Easter brings together the study (one might almost say, the scientific study) of computation with analogical theology, historical learning, and the homiletic use of history. This well illustrates the integrated nature of his superficially diverse works" (J. Campbell, ODNB
The first chapter of the chronological work, entitled "Book on calculating or speaking with fingers", describes a system of finger reckoning (up to 9,999 on two hands, though rarely used for numbers over 100).