Examples: LXIV=64, CCXXVI=226, CM=900, CMXCVIII=998 or
MDCCXII=1712
You don't find the words Roman
numbers in an encyclopedia or a reference book of mathematics. Otherwise
you could think that the Romans had their own numbers and didn't use the
natural numbers. Obviously Roman numbers mean the way of writing a number.
- On the other hand you must not be too exact in number names. A number
like MDCCXII is called a Roman number and is understood as that.
I say this because google.com e.g. finds many web sites only with the string " roman numbers".
You can keep the values in your mind as follows.
You must not think that the numerals developed this way
in former times.
Sometimes there are numbers with a numeral of a smaller value on the left side. This happens twice in CMXLVIII. Here you calculate the differences CM=M-C=1000-100=900 and XL=L-X=50-10=40 first and then you add: CMXLVIII = CM+XL+V+I+I+I = 900+40+5+1+1+1=948. From the Decimal to the Roman System If you have the opposite problem to convert a number written in Arabic numerals to one in Roman numbers, choose numbers without 4 or 9 in the beginning. An example is 1687. You break the number into thousands, hundreds, tens and units. In a second step you also consider the numbers 5, 50 and 500 (if possible) in the reduction. 1687=1000+600+80+7=1000+500+100+50+10+10+10+5+1+1=MDCLXXXVII In the end you use Roman numerals. If the number has 4 or 9, you must take differences. Take the example 1942. Use the difference M-C=CM for 900 and L-X=XL for 40. Then you add: 1942 = 1000+900+40+2 = M+CM+XL+II = MCMXLII. Maybe this way of using differences is confusing. Obviously
one wanted to avoid four equal letters side by side.
And where is the sign for the Roman zero? There is none, because there is no need for zero.
The "old Romans" used four equal numerals like IIII, XXXX, CCCC and MMMM and didn't allow differences. The letters D and M as numerals came up later. The Roman numerals spread in many countries up to the end of the Middle Ages. So you can understand that there were and are many different ways of writing the numbers during the centuries. In this respect the rules I describe on this page and which are used in schools are constructed in some way, but have become standard today. Maybe the main reason is that the writing is definite.
If the sum is a date, you call words or sentences chronograms.
The Priest Johann Loofher lived in my hometown Bad Salzuflen around 1630.
He designed Latin house inscriptions as chronograms for several houses.
The year of building was hidden in the inscriptions. You can read more
about this on my page chronograms.
The number 666 came in twilight, because it was called
the "number of the animal" in the Bible:
Consequently people found 666 in the Roman emperors' names
Nero and Deocletian, because they persecuted Christians.
The Pope's example uses the principle of the chronogram. The Pope was called VICARIUS FILII DEI (Representative of God's son). If you add the values of the Roman numerals, you get 666 ( VICARIVS FILII DEI).
Look on the internet with the string 666 and you are flooded
with informations, if you like.
near Most frequently you see Roman numerals on clocks. Some public clocks of my hometown Bad Salzuflen follow as examples. Watch maker shops use large clocks for gaining attention. They prefer decorative Roman faces to show their high quality.
This is one explanation. Please look at Gordon T. Uber's page, URL below for further informations.
far away
German Horst Hicke (Unterrrichtsmaterial-schule.de)
matroid
Michael Bradke
Wikipedia
Wolfgang Back
English Christopher Handy
Gordon T. Uber
Jim Loy
novaroma
Paul Lewis
Wikipedia
Feedback: Email address on my main page
This page is also available in German. URL of
my Homepage:
© 2003 Jürgen Köller |