Roman Numerals or Roman Numbers

Roman Numerals or Roman Numbers

Roman Numerals or Roman Numbers are system of numerical notations used by Romans. This is an additive and subtractive system in which letter are used denote certain 'base' numbers, and arbitrary numbers are then denoted using combinations of symbols. 

          Roman Numerals or Roman Numbers are represented by seven defferent letters I, V, X, L, C, D and M. Which represent the numbers 1, 5, 10, 50, 100, 500 and 1000 respectively. These seven letters are used to make thousands of numbers.

e.g.- (1) Roman numeral for 2 is written as 'II', just two one's added together.

        (2) Roman numeral for 3 is written as 'III', just three one's added together.

Origin of Roman Numerals

                                                                          There is many theory proposed in respect of origin of Roman Numerals but the most well known theory for the origin of the roman Numerals of Roman Numbers is that the numbers represent hand signals.

                The numbers ; one, two, three and four are signaled by the equivalent amount of fingers. The number five is represented by the thumb and fingers separated, making a 'V' shape. The numbers; six, seven, eight and nine are represented by one hand signalling a five and the other representing the number 1 to 4. The number ten is represented by either crossing the thumbs or hands, signalling an 'X' shape.

Symbols used in Roman Numerals

                                                             The Roman Numerals are represented by seven different symbols-

Hindu Arabic Numeral	Roman Numeral
1	I
5	V
10	X
50	L
100	C
500	D
1000	M

Basic Combinations
                               

Hindu Arabic Numeral	Roman Numeral
1	I
2	II
3	III
4	IV
5	V
6	VI
7	VII
8	VIII
9	IX
10	X
20	XX
30	XXX
40	XL
50	L
60	LX
70	LXX
80	LXXX
90	XC
100	C
200	CC
300	CCC
400	CD
500	D
600	DC
700	DCC
800	DCCC
900	CM
1000	M

Roman Numerals Chart

                                           Chart of Roman Numerals or Roman Numbers from 1 to 100  is given below-

Rules for making Roman Numeral 
                                                                                            There are few rules for writing numbers with Roman Numerals or Roman Numbers-

Rule-1:- Repeating a numeral up to three times represents addition of the number.
  e.g.- III represents 1+1+1=3
          XXX represents 10+10+10=30
          CCC represents 100+100+100=300
          MMM represents 1000+1000+1000=3000
Note:- Only I, X, C and M can be repeated. V, L and D cannot be repeated.

Rule-2:- Writing numerals in expanded form that decrease from left to right represents addition of the numbers. Writing a smaller numeral to the right of a larger numeral represents addition.
   e.g.- LX represents 50+10=60
           XVI represents 10+5+1=16
          XXVII represents 10+10+5+1+1=27

Rule-3:- To write a number that would take repeating of a numeral four or more times, there is a subtraction rule. Writing a smaller numeral to the left of a larger numeral represents subtraction.
   e.g.- IV represents 5 - 1 = 4
           IX represents 10 - 1 = 9
           XL represents 50 - 10 = 40
           XC represents 100 - 10 = 90
          CD represents 500 - 100 = 400
          CM represents 1000 - 100 = 900
Note:- V, D and M cannot be used before larger numeral.

Rule-4:- To represent larger numbers, a bar (venniculum) over a numeral means to multiply the number by 1000.
   e.g.-

Note:- 'I' cannot be used to represent a larger number.

Rule-5:-  Fraction and Zero-  fractions were often used in currency. The most common fractions used were 'twelfths' and 'halves'. A 'twelfths' is represented by a single dot '.', which is known as 'uncia'. A half is represented by the letter 'S', which is short of 'semis'

                   There is no numeral to represent 'zero'. This is because the system of Roman numbers was developed as a means of trading and there was no need for a numeral to represent zero. Instead they would have used the Latin word 'nulla' which means zero.

    we can say that,

        Fraction                   Roman Numeral          Name                      Meaning

       1/12                               .                               Uncia                        Ounce
         1/2                                  S                               Semis                        Half
          1/3                                 ....                             Triens                        Third
          1/4                                 ...                              Quadrans                   Quarter
          0                                     N                              Nulla                         Zero
Note:- Generally these symbols are not used in Roman Numerals now a days.

Modern use of Roman Numerals
                                                                                       Modern uses of  Roman Numerals are given as-

(1) Roman Numerals are used to refer to kings, queens, emperors and popes.
     e.g.- Elizabeth II and Lois XVI
(2) Many competitions such as the Olympic Games use to numerals to represent how many times the event has been held.
    e.g.- The Olympic games in Tokyo (2020) will be the thirty second time. This can be represented by the numerals XXXII.
(3) Numerals can often be found on buildings and monuments to signify the year of construction.
    e.g.- A building built in 2004 may have the numerals MMIV on it.
(4) Many clocks also use Roman Numerals to represent the hours.
(5) Many movies use numerals to illustrate the year the film was made.
  e.g.- 'Mission Mangal' was copyrighted in the year 2019, so it has the numeral MMXIX at the end of its credit.