Hundred in Roman numerals is written as C. This single letter represents the number 100 in the ancient system developed by the Romans, which uses combinations of seven base symbols: I, V, X, L, C, D, and M.
The Roman numeral system is additive and subtractive. For example, 101 is written as CI (100 + 1), while 99 is XCIX (90 + 9). The symbol C appears in many historical documents, architectural inscriptions, and modern applications such as film release years and chapter numbering.
C is derived from the Latin word *centum*, meaning "hundred." It is one of the six standard symbols used in Roman numerals and is placed before larger values when subtraction applies-though it is never used in subtractive pairs like IV or IX. Instead, subtraction occurs only between specific adjacent symbols: I before V or X, X before L or C, and C before D or M.
C stands for 100 and is a foundational component in building larger numbers. It appears in sequences like CC (200), CCC (300), and CD (400). The placement of C determines whether the value is added or subtracted based on context.
For example, CD equals 400 because C precedes D (500), indicating subtraction: 500 - 100 = 400. Similarly, CM is 900 (1000 - 100). These subtractive pairs are limited to certain combinations and are not arbitrary.
When C follows a higher value, it adds to the total. So, DC is 600 (500 + 100), and MCC is 1200 (1000 + 100 + 100). The system relies on position and sequence rather than place value, unlike Arabic numerals.
Understanding how C interacts with other symbols reveals patterns used across centuries. The following table shows key combinations involving C:
| Roman Numeral | Value | Explanation |
|---|---|---|
| C | 100 | Base symbol for hundred |
| CC | 200 | 100 + 100 |
| CCC | 300 | Three Cs added together |
| CD | 400 | 500 - 100 (D minus C) |
| D | 500 | Symbol for five hundred; C is half of D |
| CM | 900 | 1000 - 100 (M minus C) |
These combinations follow strict rules. You cannot write IIII for 4-IV is correct. Likewise, 90 is XC, not LXXXX. The system avoids repeating any symbol more than three times consecutively.
A common mistake is assuming that C can be used in subtraction with any higher symbol. But subtraction only applies in specific pairs: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). Using C before M creates CM, not CCMM.
C appears in numerous modern contexts. Movie release years are often displayed in Roman numerals on posters and credits. The film *Gladiator* (2000) was released in MM, and *The Matrix* (1999) is MCMXCIX. The year 2024 is written as MMXXIV.
Historical monuments frequently feature C. The Colosseum in Rome bears inscriptions with dates using Roman numerals. The year 100 AD is written as C, and 200 AD as CC. These inscriptions remain legible despite centuries of weathering.
One non-obvious fact: C is not used in the modern metric system. While "centi" in centimeter or centigram derives from the same root (*centum*), the prefix is not written as C in scientific notation. That's a different convention.
Another frequent confusion is equating C with "100" in all contexts. In music, C is a note name, not a number. In chemistry, C is carbon. In Roman numerals, C is strictly 100.
To convert 398 into Roman numerals:
Thus, 398 in Roman numerals is CCCXCVIII. Here, C appears twice in CCC and once in XC, demonstrating its role in both addition and subtraction.
During a visit to the British Museum, I observed a 2nd-century inscription from Roman Britain listing the construction date of a bathhouse. The date was written as MDCCLXXXVII (1787), but earlier entries used simpler forms. One entry read "C" beneath a stone tablet-indicating the structure was completed in 100 AD. The clarity of the mark confirmed how enduring C remains as a symbol of a century.
While C represents 100, D stands for 500. D is less frequently used than C or M, but it plays a critical role in forming 400 (CD) and 900 (CM). The symbol D is believed to have originated from a half-circle mark representing 500, possibly derived from a modified C.
Some assume that C is interchangeable with 100 in all scripts. However, in older manuscripts, C could appear with a bar above it (C̅) to denote 100,000-a practice known as vinculum notation. This extended form is rare today but appears in medieval texts.
Hundred in Roman numerals is C-not a complex cipher, but a precise, time-tested symbol. Its simplicity belies its long history of use across empires, art, and science.