Talk:Roman abacus

message: I have been trying to determine how the fractional columns are applied in the Roman Abacus, in part to determine what fractional representations where used (with the view that the Roman number system is essentially a transcription of the Abacus).
There are a number of other illustrations or pictures of abaci or replicas online.  But the most interesting reference was to Frontinus on the Water Supply of Rome, which includes a number of fractional numbers, with symbology which can be related to the abacus (I dont have access to pre-typeset versions of this document, so I am relying on the referenced version and a couple of other online versions).
Fractional numbers are shown in Frontinus as: 'XVII S ==- £ 3 VI' (my spacing).  The 'XVII' is the integer part, 'S' represents 'semis' (1/2) as necessary, '==-' (dots or dashes) mark uncia (1/12) upto 5/12th.  The '£' is interpreted as half-uncia (1/24th), and appears to be the same symbol as written '~3' in the Wiki article.  The '3' is actually ')-bar' (reverse-C with horizontal bar through centre), indicates scripulum (1/288), and the 'VI' is the number of scripula (upto XI, 'I' may be omitted). 
Onto the Abacus...
Firstly, the Uncia column, labelled O-bar here, is fairly straight forward.  Other illustrations show 5 lower and 1 upper bead, thus representing 1/12ths -- upper bead = 6/12 = 1/2, representing by 'S' (semis) in writing, lower beads 0-5/12, represented by dashes.  This is essentially the same as the integer multiple columns to the left.
The three short fraction columns, labelled '~3' (cf. '£'), ')' and '2', appear as seperate columns with their own beads in some instances, and as a single column with three labels (as per the diagram) in others.  I strongly suspect that the correct interpretation is as seperate columns, with single-columns variations being split into three domains for operation (after all, you cannot unsplit the first case).
The top column, labelled '~3' or '£' (or capital-sigma), contains a single bead, which maps to a representation of half-uncia, or 'semuncia'.  This corresponds to the notation in Frontinus.
The middle column, labelled ')', holding two beads would represent 'sextulae', 1/6-uncia.  These are not represented independantly in Frontinus.
Finally, the lower column, labelled '2', is still uncertain.  If this represents scripula (1/288, 1/24 uncia) then there should be three beads (four scripula to the sextulae).  The only clear examples show 2 beads -- but it is not impossible that one has been lost...  The symbol '2' could be related to the ')-bar' used in Frontinus for scripula: ')' + '-' becomes ')' + '_' becomes '2'.
So, it does appear to be possible to reconcile the all the Abacus fields with the fractional numbers represented in Frontinus.  Does this make sense?
--Sawatts 23:13, 7 Dec 2004 (UTC)
thread_title:  Fractional Columns 

message: There are some obvious historical problems with this article.  It is by no means clear to me that Roman trade was the engine of the Empire, or even significant to the population.  There is no evidence of trasference to China and it is not clear that the Roman counting board predates the Chinese abacus.  With all due respect to the Romans, their counting board is a counting board and so similar to the Salamis counting board for instance, as well as other ad hoc counting devices going back to Sumer.  It is not an abacus which has beads on wires or strings (as opposed to groves).  On top of which this article looks awfully similar to some others on the internet.  Which came first?  Anyone know if this is someone else's work or not? Lao Wai 14:21, 7 August 2005 (UTC)
thread_title:  Historic and Copyright problems 

message: The construction of the Soroban has rods and beads, making it physically similar to the Chinese suanpan.
The Roman abacus has fewer rows than either the suanpan or soroban, and it is in grooves.
How "similar" can the two be? Not very.  —Preceding unsigned comment added by Facial (talk • contribs) 22:11, 9 December 2007 (UTC)
thread_title:  Similar to Soroban?... errr, not really 

message: I have redirected Roman arithmetic here as there seems to be no evidence that they ever did arithmetic with Roman numerals. Possibly this article could have a little bit more about roman arithmetic but I can't think of much to say except that the evidence is they either used their fingers or an abacus. I can see no reason they would even do mental arithmetic with Roman numerals, Japanese schools teach using the soroban and people are that transfers well to them using a mental soroban, very often they're even faster and more accurate doing it mentally. Dmcq (talk) 19:31, 21 October 2011 (UTC)
thread_title:  Have redirected roman arithmetic here 

message: I have removed the following section which seems to be original research.  If citations can be provided, it can be reinstated, though without the repeated references to the author himself and his education. Mnudelman (talk) 14:15, 10 April 2015 (UTC)
thread_title:  Removed original research 

message: This lead section may not follow Wikipedia's Manual of Style. Parts are written with lots of opinion, i.e. "But language, the most reliable and conservative guardian of a past culture, has come to our rescue once more." The information is there, but it's just not presented properly. Bass77 (talk) 00:26, 15 February 2017 (UTC)
thread_title:  Tone of Lead Section