99 in Roman numerals

99 in Roman numerals is XCIX.

Pick any whole number from 1 to 3,999.

99 = \text{XCIX}

How to work it out

1
Take the biggest Roman value that fits, write its letter, subtract it, and repeat.
2
Here: 90 (XC) + 9 (IX) = 99.
3
Joined together: XCIX. (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
90	XC
9	IX

What is 99 in Roman numerals?

XCIX.

How do you read XCIX?

XCIX = 90 + 9 = 99.