What Is The Roman Numeral For 25?

The number 25 is written as XXV in Roman numerals.  If you're looking for a table showing the Roman numerals I'd suggest the following link: Roman numerals
The number 25 in Roman numerals The way Roman numerals work is that there is a list of basic numbers, and then more complicated numbers are made by putting these numbers together in a certain way.
The basic Roman numerals include:
I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1000

To make a number like 25, you would use XX (two tens) to make twenty, and then you would add a V at the end for 5.
Adding an additional number after the main symbol is the main way increase a number.
So, for example, 101 would be written as CI because C is 100, and I is 1.
To write a number that is in between two major symbols, you would use the shortest transcription.
For example the number 4 could be written as IIII, but this isn't the shortest way of representing that amount, and so isn't employed.
Instead, Romans would write 4 as IV.
This is because V is the symbol for 5, and having I before it means that you actually take away I from V (or 1 from 5) making 4.

XXV=25 where X=10 and V=5.