729 in Roman numerals

729 in Roman numerals is DCCXXIX.

Pick any whole number from 1 to 3,999.

729 = \text{DCCXXIX}

How to work it out

1
Take the biggest Roman value that fits, write its letter, subtract it, and repeat.
2
Here: 500 (D) + 100 (C) + 100 (C) + 10 (X) + 10 (X) + 9 (IX) = 729.
3
Joined together: DCCXXIX. (Four of the same letter in a row is never used: 4 is IV, 9 is IX, 40 is XL, 90 is XC, 400 is CD, 900 is CM.)

What is 729 in Roman numerals?

DCCXXIX.

How do you read DCCXXIX?

DCCXXIX = 500 + 100 + 100 + 10 + 10 + 9 = 729.