The
Etruscan numerals were used by the ancient
Etruscans. The system was adapted from the Greek
Attic numerals and formed the
inspiration for the later
Roman
numerals.
Etruscan 
Decimal 
Symbol * 
θu 
1 

maχ 
5 

śar 
10 

muvalχ 
50 

? 
100 
or C 
There is very little surviving evidence of these numerals. Examples
are known of the symbols for larger numbers, but it is unknown
which symbol represents which number.
Thanks to the numbers written out on the
Tuscania dice, there is agreement about the
fact that
zal,
ci,
huθ and
śa are the numbers up to
6 (besides 1 and 5). The assignment depends on the answer to the
question whether the numbers on opposite faces on Etruscan dice add
up to seven, like nowadays. Some dice found don't show this
proposed pattern.
An interesting aspect of the Etruscan
numeral system is that some numbers, as in
the Roman system, are represented as partial subtractions. So "17"
is not written *semφśar as users of the
Arabic numerals might reason. We instead
find — literally, "three away from twenty". The numbers 17, 18 and
19 are all written in this way.
The general consensus
Despite the continuing debate specifically about which of huθ and
śa are "four" and "six", the general agreement among Etruscologists
nowadays is the following:
Etruscan 
Decimal 
θu 
1 
zal 
2 
ci 
3 
huθ 
4 
maχ 
5 
śa 
6 
semφ 
7 
cezp 
8 
nurφ 
9 
śar 
10 
*θuśar 
11 
*zalśar 
12 
*ciśar 
13 
huθzar 
14 
*maχśar 
15 
*śaśar 
16 
ciem zaθrum 
17 
eslem zaθrum 
18 
θunem zaθrum 
19 
zaθrum 
20 
cealχ 
30 
*huθalχ 
40 
muvalχ 
50 
śealχ 
60 
semφalχ 
70 
cezpalχ 
80 
*nurφalχ 
90 

Recently (2006) S. A. Yatsemirsky (
PDF) has presented evidence that
zar
=
śar meant ‘12’ (cf.
zal ‘2’ and
zaθrum ‘20’) while
halχ meant
‘10’. According to his interpretation the attested form
huθzar was used for ‘sixteen’, not
‘fourteen’.
The words for 17, 18, and 19 may have influenced Latin
duodeviginti (18) and
undeviginti (19), literally
"twofromtwenty" and "onefromtwenty" (with Etruscan
(n)em apparently meaning "from"). Both these forms of 18
and 19 have disappeared from modern Romance languages.
The numerals seem to show that Etruscan is not an
IndoEuropean language, because of the
apparent impossibility in finding viable regular sound change
correspondences between the Etruscan numerals and those in
ProtoIndoEuropean.
See also
External links
 http://users.tpg.com.au/etr/etrusk/tex/grammar.html#num
 http://www.mysteriousetruscans.com/language.html