28
GREEK NUMERICAL NOTATION
EG
parts, except f, which had a special sign <^> or < j : r > ; the
submultiples were denoted by writing <zr> over the corre
sponding whole number; thus
mTni = -is > QQQ Hfl = xii 77 <2 nnn = TiVo •
HU && nm
Babylonian systems.
(a) Decimal. (/3) Sexagesimal.
The ancient Babylonians had two systems of numeration.
The one was purely decimal based on the following signs.
The simple wedge | represented the unit, which was repeated
up to nine times: where there were more than three, they
were placed in two or three rows, e.g. Xjft = 4, y|| = 7. 10
was represented by 11 would therefore be . 100 had
the compound sign and 1000 was expressed as 10 hun
dreds, by the prefixed ^ (10) being here multiplicative.
Similarly, the was regarded as one sign, and «1- de
noted not 2000 but 10000, the prefixed ^ being again multi
plicative. Multiples of 10000 seem to have been expressed
as multiples of 1000; at least, 120000 seems to be attested
in the form 100.1000 + 20.1000. The absence of any definite
unit above 1000 (if it was really absent) must have rendered
the system very inconvenient as a means of expressing large
numbers.
Much more interesting is the second Babylonian system,
the sexagesimal. This is found in use on the Tables of
Senkereh, discovered by W. K. Loftus in 1854, which may go
back as far as the time between 2300 and 1600 b.c. In this
system numbers above the units (which go from 1 to 59) are
arranged according to powers of 60. 60 itself was called
sussu ( = soss), 60 2 was called sar, and there was a name also
(ner) for the intermediate number 10.60 = 600. The multi
ples of the several powers of 60, 60 2 , 60 3 , &c., contained in the
number to be written down were expressed by means of the
same wedge-notation as served for the units, and the multi
ples were placed in columns side by side, the columns being
appropriated to the successive powers of 60. The unit-term
was folic
success! v
&c., beh:
Thus g
«Rf <
larly we
represent
Babylon!
is here v
The si
for 0 (in
and a fi:
position-'
system 0
Senkerel
appears i
used for
inconven
cation ta
however,
expressin
Hilprechi
part in '
= 60 8 + ]
units of 8
notation,
gesimal.
the base <
the authc
of a base
advantag
To reti
all dates,
but the ;
things as
made to