A history of Greek mathematics - Wilbourhall.org

;
;
;
;
'
MOSCHOPOULOS. RHABDAS 551
of Smyrna, arithmetician and geometer, tov 'Pa/3oi).
(a) On the left hand :
for 1,
half-close the 5th finger only;
„ 2, „ „ 4th and 5th fingers only
., 3, „ ,, 3rd, 4th and 5th fingers only
„ 4, „ „ 3rd and 4th fingers only ;
„ 5, „ „ 3rd finger only
„ 7, close the 5th finger only;
„ 8, „ „ 4th and 5th fingers only
„ 9, „ „ 3rd, 4th and 5th fingers only.
(6) The same operations on the right hand give the thousands,
from 1000 to 9000.
(c) On the left hand :
for 10,
apply the tip of the forefinger to the first joint of
the thumb so that the resulting figure resembles o~ ;
1
A similar description occurs in the works of the Venerable Bede
(' De computo vel loquela digitorum ', forming chapter i of De temporum
ratione), where expressions are also quoted from St. Jerome (d. 420 A. d.)
as showing that he too was acquainted with the system (The Miscellaneous
Works of the Venerable Bede, ed. J. A. Giles, vol. vi, 1843, pp. 141-3).