900 in Roman Numerals
900 in Roman numerals is CM. It is built from one part: 900 = CM. Read it from left to right and add the values to get 900. Copy it below, see why it is written this way, and check the numbers before and after. The converter handles any number from 1 to 3,999.
900 in Roman numerals is CM.
900 in Roman numerals: the breakdown
| Place value | Numeral | Value |
|---|---|---|
| 900 | CM | 900 |
| Total | CM | 900 |
900 is a single place value, so CM on its own is 900.
Why CM and not DCCCC?
CM uses the subtractive pair CM. Written by adding only, 900 would be DCCCC, but a letter may repeat only three times in a row, and DCCCC repeats C four times.
How to read CM
- CM is 1000 minus 100, which is 900.
- There is nothing else to add, so CM is 900.
The numbers around 900
Facts about 900
- 900 is an even number.
- 900 is not prime: 900 = 2 x 2 x 3 x 3 x 5 x 5.
- 900 is a perfect square: 30 x 30 = 900.
- The digits of 900 add up to 9.
- CM is 2 letters long. It uses the symbols M and C.
Convert another number
What number is CM?
CM is the number 900. It is a single place-value part, so reading it from left to right gives 900 straight away.
Questions and answers
What is 900 in Roman numerals?
900 in Roman numerals is CM. It is made of one part: 900 = CM. Read CM from left to right, add the parts, and you get 900. Use the converter on this page to check any other number from 1 to 3,999.
How do you write 900 in Roman numerals?
Split 900 into its place values, write each one in Roman numerals, and join them from largest to smallest. For 900 there is only one place value, so the answer is CM. Check that no letter repeats more than three times in a row.
What number is CM?
CM is 900. Read it from left to right: it is a single place-value part, CM, which is 900, so there is nothing else to add. Letters after a larger or equal letter are added, and a smaller letter before a larger one is subtracted. You can also type CM into the converter to read the number back.
Why is 900 written CM and not DCCCC?
CM is the standard form. DCCCC breaks a rule: a letter may repeat only three times in a row, and DCCCC repeats C four times. Writing CM keeps every letter within those limits and makes 900 easy to read at a glance.