550 in Roman numerals

550 in Roman numerals is DL.

Pick any whole number from 1 to 3,999.

550 = \text{DL}

How to work it out

1
Take the biggest Roman value that fits, write its letter, subtract it, and repeat.
2
Here: 500 (D) + 50 (L) = 550.
3
Joined together: DL. (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
50	L

What is 550 in Roman numerals?

DL.

How do you read DL?

DL = 500 + 50 = 550.