The method of indicating numbers by means of the fingers is of
considerable age. The British Museum possesses two ivory counters marked
on one side by carelessly scratched Roman numerals IIIV and VIIII, and
on the other by carefully engraved digital signs for 8 and 9. Sixteen
seems to have been the number of a complete set. These counters were
either used in games or for the counting board, and the Museum ones,
coming from the Hamilton collection, are undoubtedly not later than the
first century. Frohner has published in the _Zeitschrift des Münchener
Alterthumsvereins_ a set, almost complete, of them with a Byzantine
treatise; a Latin treatise is printed among Bede’s works. The use of
this method is universal through the East, and a variety of it is found
among many of the native races in Africa. In medieval Europe it was
almost restricted to Italy and the Mediterranean basin, and in the
treatise already quoted (Sloane 3281) it is even called the Abacus,
perhaps a memory of Fibonacci’s work.
Methods of calculation by means of these signs undoubtedly have existed,
but they were too involved and liable to error to be much used.