2. ROMAN NUMERALS
Roman numerals originated, as the name
might suggest, in ancient Rome. There are
seven basic symbols: I, V, X, L, C, D and M.
The first usage of the symbols began
showing up between 900 and 800 B.C.
3. Roman Numerals
The numeric system known today as Roman
Numerals utilizes only seven symbols, which
are added and subtracted to form any
number. A superscript bar over a number
multiplies it by 1,000, and two vertical lines in
addition to the superscript bar multiply a
number by 100,000. Thus the common
symbols are:
4. Roman Numerals
However, their number system was flawed, it
had no zero (0), and no single method for
counting above several thousand units, (lines
were often placed over numerals to indicate
multiples of their value).
5. Roman Numerals
The eventual fall of the Roman Empire by 300
A.D. saw the introduction and adoption of
Arabic numerals, today we call them decimal
numbers because they work consistently to a
base of 10. The invention of zero (nothing)
was a huge leap forward.
6. Roman Numerals
Uses of Roman numerals
Roman numerals today are used most
frequently seen as list numbers, time pieces
and historic Roman coins, art and antiquities
in museums and antique shops. Nearly all
computer word processing packages (Word,
PDF) allow uppercase and lowercase Roman
numerals as list item indicators.
7. Roman Numerals
Uses of Roman numerals
Roman numerals today are used most
frequently seen as list numbers, time pieces
and historic Roman coins, art and antiquities
in museums and antique shops. Nearly all
computer word processing packages (Word,
PDF) allow uppercase and lowercase Roman
numerals as list item indicators.
8. Roman Numerals
Uses of Roman numerals
Roman numerals are used in astronomy to
designate moons and in chemistry to denote
groups of the Periodic Table. They can be seen
in tables of contents and in manuscript
outlines, as upper- and lower-case Roman
numerals break information into an easily
organized structure.
9. Roman Numerals
Disadvantages of using Roman numerals
Roman numerals are not without flaws. For
example, there is no symbol for zero, and
there is no way to calculate fractions. This
hindered the ability to develop a universally
understood, sophisticated math system, and
made trading more difficult.
10. Roman Numerals
Disadvantages of using Roman numerals
Eventually, Roman numerals gave way to the
more versatile Arabic or Hindu numeral
system, where numbers are read as a single
number in sequence, like 435 as four hundred
thirty-five.
12. Roman Numerals
There was no symbol for zero
The rule is that when two figures are side by
side, if the smaller is on the right, it is added
to the larger, and if it is on the left, it is
subtracted from the larger. So, VI = 6 and IV =
4. Exceptions to this rule are very rare.
13. Roman Numerals
Modern rules have also been added, and are that:
• No more than three of the same symbol can be repeated in a row, and V
and L are never repeated.
• The smaller number preceeding a larger number cannot be more than two
values lower than the other or be one-half of it. This leaves IV, IX, VL, XL,
XC, LD, CD, and CM as the normal pairings, so we will most likely see 1999
written as MCMXCIX rather than MIM.
14. Roman Numerals
In reality, these rules were never followed by the Romans. To
start, they used more than these seven symbols, and M was
used only as an abbreviation of mille or milia, not used in
combination with other symbols until the 15th century.
Repetitions of numbers often exceeded the rule of three, but V
and L were never repeated. Values including VIIII and even
XXXXXX were common. The following table shows how much the
symbols vary.
15. 1. I 15. XV
2. II 16. XVI
3. III 17. XVII
4. IIII or IV 18. XVIII or XIIX
5. V 19. XIX or XVIIII
6. VI or 20. XX
7. VII 30. XXX
8. VIII or IIX 40. XL or XXXX
9. VIIII or IX 50. L
10. X 60. LX
11. XI 70. LXX
12. XII 80. LXXX or XXC
13. XIII 90. XC or LXXXX
14. XIV
100. C
