Today's post shall be on Roman numbers.
Roman numerals is the numeral system of Ancient Rome. It is based on the letters of the alphabet which are combined to signify the sum of their values.
For example, the first ten numbers in Roman numerals would be:
Roman: I, II, III, IV, V, VI, VII, VIII, IX, X
Numerical: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
From here we can see that I means 1, V means 5, and X means 10. Placing an I in front of another letter means deducting 1 from the value of the 2nd letter, like how IV is 5-1=4 and IX is 10-1=9. Placing 1 or more Is behind another letter means adding that number of '1's to the value of the other letter, like VI is 5+1=6, VII is 5+2(1)=7.
There is no zero in Roman numerals.
The Roman numerals is the "cousin" of the Etruscan numerals. The letters used to represent the different values actually originate from non-alphabetical symbols, with which over time, the Romans eventually identified the symbols with letters of their Latin alphabet. No doubt, despite this numbering system being that of ancient times, it is still used in our lives today; they are most commonly seen in numbered list, clock faces, pages preceding the main body of the book etc.
Other than I, V and X, there are also other letters used to represent the different values:
L - 50
C - 100
D - 500
M - 1000
However, the system we used today is not what this numeral system originated as. Initially, the Romans only used capital letters, I II III etc. However, in the Middle Ages, the system was modified to eventually produce the system that we used today, which includes minuscule(lower case) letters. It was then that these minuscule letters were developed, e.g.: i, ii, iii etc.
It is interesting to note that people substituted the last i of a numeral with j, making 8 viij, etc.. This is done so as to prevent tampering with numbers after they have been written, for example in medical prescriptions, etc.
Also, for large numbers(in the thousands), a bar can be placed above the base numeral, or parentheses placed around it. This indicates the multiplication of 1000.
As such:
_
V or (V) represents 5000, etc..
Deeper into its roots:
Roman numerals originally intended as independent symbols, derived from notches on tally sticks.
'I' was meant to be a notch scored across the stick, with every fifth notch being a double cut, i.e. Λ, V and a few other variations, while every tenth was a cross cut, X. 50 was written as V with an extra stroke, with its variations being N, И, K, Ψ, ⋔, etc.. However, it was most often written as ᗐ, which was later 'flattened' and eventually becoming a symbol similar to 'L'. Similarly, 100 was intended as an addition of a stroke to X, Ж, which evolved to ƆIC, finally was abbreviated to C. 500 was intended as a Ɔ superposed on a ⊢, producing D, 1000 was a circled X, Ⓧ becoming M after the Middle Ages.
So the numbers was written as:
IIIIΛIIIIXIIIIΛIIIIX...
The above produced a positional system, like how 13, being the 3rd notch after the first ten, which could be abbreviated as X, became XIII and thus the positioning of this unique system.
Fractions:
Fractions in Roman numerals were based on 12, due to its divisibility (12=3x2x2), making it easier to handle the common fractions of 1/3 and 1/4. A dot '.' indicated a "twelfth", and 6 of these makes a half, denoted by S. As such, the Roman representation of fractions are as follows:
1/12 -> .
2/12 = 1/6 -> :
3/12 = 1/4 -> ∴
4/12 = 1/3 -> ∴
5/12 -> :•:
6/12 = 1/2 -> S
12/12 = 1 -> I
From from 7/12 onwards, it is just the addition of the dots behind S, like 10/12 = 5/6 is represented by S::
Ok, that's all for Roman numerals..
Cheers,
Kah Keong
