Number
340 in Roman numerals
340 is written CCCXL
Type any other number or numeral below to convert it.
Above 3,999? Type the barred part in brackets, e.g. (IV)CC = 4,200.
How CCCXL is built
Roman numerals are written one decimal place at a time, largest first.
- CCChundreds · 3C written 3 times: 3 × 100 = 300.
- XLtens · 4X before L means 50 − 10 = 40. This saves writing XXXX.
300 + 40 = 340
The pair XL uses subtraction: a smaller letter before a larger one is taken away from it. Only six pairs work this way: IV, IX, XL, XC, CD and CM. More on subtraction
Mistakes to avoid
- Not CCCXXXX (7 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today CCCXL (5 letters) is the standard.
- There's no letter for zero. The zero is simply left out, which is why 340 has 2 parts, not 3.
About the number 340
- 340 is even and can be split into prime factors: 2 × 2 × 5 × 17, or in Roman numerals II × II × V × XVII.
- CCCXL has 5 letters. 604 of the numbers up to 1,000 have longer numerals.
Counting from 331 to 340
Every number from 331 to 340 starts CCCX (310); only the ending changes.
| Number | Roman numeral |
|---|---|
| 331 | CCCXXXI |
| 332 | CCCXXXII |
| 333 | CCCXXXIII |
| 334 | CCCXXXIV |
| 335 | CCCXXXV |
| 336 | CCCXXXVI |
| 337 | CCCXXXVII |
| 338 | CCCXXXVIII |
| 339 | CCCXXXIX |
| 340 | CCCXL |