29 in Roman numerals at a glance
- Roman numeral
- XXIX
- Lowercase
- xxix
- Letters
- 4
- Parts
- X · X · IX
- Subtractive pairs
- IX
- In words
- twenty-nine
- Latin name
- undetriginta
How XXIX is built
Roman numerals are written one decimal place at a time, from the largest place to the smallest. Converting each digit of 29 separately and joining the pieces gives XXIX:
| Place | Digit | Value | Numeral |
|---|---|---|---|
| Tens | 2 | 20 | XX |
| Ones | 9 | 9 | IX |
Reading it back, left to right:
- X = 10 → running total 10
- X = 10 → running total 20
- IX = 9 (X minus I) → running total 29
The rules XXIX follows
- Largest to smallest. XXIX uses the symbols X and I (4 characters in all), and the values never increase from left to right except inside a subtractive pair.
- Subtraction. IX (9) is a subtractive pair: a smaller symbol in front of a larger one is taken away from it. Only six pairs are allowed — IV, IX, XL, XC, CD and CM — and XXIX uses one of them.
- Repetition. XX repeats X two times. I, X, C and M may repeat up to three times in a row; V, L and D never repeat.
Common mistakes when writing 29
- XXVIIII — wrong because standard numerals never repeat a symbol four times; 9 is written IX. The correct form is XXIX.
Where you will see XXIX
- The modern Summer Games. They are officially numbered by Olympiad; the Games of the XXIX Olympiad belong to 2008: Beijing.
- Championship games. Pro football numbers its championship game with Roman numerals, starting from game I in January 1967. Game XXIX was played in early 1995.
- Volumes and sequels. Book volumes, conference editions, film sequels and anniversary events often carry a Roman numeral; edition XXIX would be the 29th.
Latin itself counted backwards here: undetriginta means “one from thirty,” the same subtractive idea that Roman numerals use in pairs such as IX and XC — although the numeral for 29 is written XXIX, not by subtracting from 30.
Numbers near 29 in Roman numerals
Frequently asked questions
How do you write 29 in Roman numerals?
29 is written XXIX. Break it into X (10), X (10), IX (9) and add the parts: 10 + 10 + 9 = 29.
Is XXVIIII a correct way to write 29?
No. XXVIIII is wrong because standard numerals never repeat a symbol four times; 9 is written IX. The standard numeral for 29 is XXIX.
What is 29 in Latin?
The Latin cardinal number 29 is “undetriginta.” The Romans wrote it as XXIX.
What is XXIX plus one?
XXIX + I = XXX (30). Adding one can change the whole ending of a numeral, which is why it helps to convert to digits, add, and convert back.