Roman Numerals

ROMAN NUMERALS

Roman numerals, originating from ancient Rome, use seven Latin letters as symbols to represent values: I=1, V=5, X=10, L=50, C=100,D=500, and M=1000. They operate primarily on an additive principle (e.g., XVI is (10+5+1=16), though smaller numerals before larger ones imply subtraction (e.g., IV is (5-1=4). Common in modern times for clocks, movie dates, and outlining, the system typically uses uppercase letters, but lowercase can be used.

CORE ROMAN NUMERALS

I = 1

V = 5

X = 10

L = 50

C = 100

D = 500

M = 1,000

Key Rules of Roman Numerals

ADDITION: When a smaller numeral follows a larger one, it is added (e.g., VI = 5 + 1 = 6).

SUBTRACTION: When a smaller numeral precedes a larger one, it is subtracted (e.g., IX = 10 - 1 = 9).

REPETITION: A symbol can be repeated up to three times consecutively to add values (e.g., # # # = 30).

NO FOUR-IN-A-ROW: A symbol cannot be repeated four times (e.g., 4 is written as IV, not IIII).

OVERLINE (Vinculum): A bar placed over a numeral multiplies its value by 1,000 (e.g., V = 5,000).

Common Examples:

1–10: I, II, III, IV, V, VI, VII, VIII, IX, X

19: XIX (10 + 9)

20: XX

40: XL (50 - 10)

50: L

90: XC (100 - 10)

100: C

400: CD (500 - 100)

500: D

900: CM (1000 - 100)

1000: M

2026: MMXXVI

MMXXVI

X
XX
# # #
C
CC
CCC
M
MM
MMM