79 in Roman numerals at a glance
- Roman numeral
- LXXIX
- Lowercase
- lxxix
- Letters
- 5
- Parts
- L · X · X · IX
- Subtractive pairs
- IX
- In words
- seventy-nine
- Latin name
- undeoctoginta
How LXXIX is built
Roman numerals are written one decimal place at a time, from the largest place to the smallest. Converting each digit of 79 separately and joining the pieces gives LXXIX:
| Place | Digit | Value | Numeral |
|---|---|---|---|
| Tens | 7 | 70 | LXX |
| Ones | 9 | 9 | IX |
Reading it back, left to right:
- L = 50 → running total 50
- X = 10 → running total 60
- X = 10 → running total 70
- IX = 9 (X minus I) → running total 79
The rules LXXIX follows
- Largest to smallest. LXXIX uses the symbols L, X and I (5 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 LXXIX 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 79
- LXXVIIII — wrong because standard numerals never repeat a symbol four times; 9 is written IX. The correct form is LXXIX.
Where you will see LXXIX
- Championship games. Pro football numbers its championship game with Roman numerals, starting from game I in January 1967. Game LXXIX falls in early 2045.
- Volumes and sequels. Book volumes, conference editions, film sequels and anniversary events often carry a Roman numeral; edition LXXIX would be the 79th.
Latin itself counted backwards here: undeoctoginta means “one from eighty,” the same subtractive idea that Roman numerals use in pairs such as IX and XC — although the numeral for 79 is written LXXIX, not by subtracting from 80.
Numbers near 79 in Roman numerals
| Number | Roman numeral | Letters |
|---|---|---|
| 75 | LXXV | 4 |
| 76 | LXXVI | 5 |
| 77 | LXXVII | 6 |
| 78 | LXXVIII | 7 |
| 79 | LXXIX | 5 |
| 80 | LXXX | 4 |
| 81 | LXXXI | 5 |
| 82 | LXXXII | 6 |
| 83 | LXXXIII | 7 |
Frequently asked questions
How do you write 79 in Roman numerals?
79 is written LXXIX. Break it into L (50), X (10), X (10), IX (9) and add the parts: 50 + 10 + 10 + 9 = 79.
Is LXXVIIII a correct way to write 79?
No. LXXVIIII is wrong because standard numerals never repeat a symbol four times; 9 is written IX. The standard numeral for 79 is LXXIX.
What is 79 in Latin?
The Latin cardinal number 79 is “undeoctoginta.” The Romans wrote it as LXXIX.
What is LXXIX plus one?
LXXIX + I = LXXX (80). Adding one can change the whole ending of a numeral, which is why it helps to convert to digits, add, and convert back.