600 in Roman numerals

600 in Roman numerals is DC.

Pick any whole number from 1 to 3,999.

600 = \text{DC}

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) = 600.
3
Joined together: DC. (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.)

Value	Letters
500	D
100	C

What is 600 in Roman numerals?

DC.

How do you read DC?

DC = 500 + 100 = 600.