MMXXV_V_XXVIII

Let’s review Roman numerals

I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1,000

2,025 = MMXXV
5 = V
25 = XXV
3,000 = MMM
3,999 = MMMIMICIX

Originally, Roman numerals only went up to 3,999.

Today, an overline or a bar is added on top to indicate the multiples of 1,000.
So for example,
4,000 = I̅V̅
5,000 = V̅
10,000 = X̅
100,000 = C̅
500,000 = D̅
1,000,000 = M̅
10,520 = X̅DXX

When feeling lazy, just use the Roman numeral converter!