The Vindolanda tablets generally use the familiar Roman system
of letters for representing numbers. Sometimes numerals are marked
by a bar above the line, usually above the number of the cohort.
Of the letters in common use, the following are used in the Vindolanda
tablets:
i (one)
v (five)
x (ten)
l (50)
c (100)
d (500)
Numbers over 1000 are represented in the Vindolanda texts by the
word mille (plural  milia). Other numbers are represented
by multiples of these symbols (e.g. iii for 3, xvii for 17, lxxviii
for 78, ccxxxi for 231). To represent 4 and 9 and numbers including
4 and 9, the Vindolanda tablets only occasionally use the 'subtractive'
system familiar to modern readers (i.e. iv for 4, ix for 9, xl for
40 and so on). They are instead more commonly indicated in the same
way as other numbers (i.e. iiii for 4, viiii for 9, xxxx for 40
and so on).
The letter s after the number indicates a half. The tablets
also contributes important information on the representation of
fractions related to money.
For further information see currency
in the reference section.
