How Roman Numerals Work

The Rules

If you have no clue how roman numerals work, here is a quick overview. Let’s start with some basic numbers:

i = 1
ii = 2
iii = 3
v = 5
x = 10
l = 50
c = 100
d = 500
m = 1000

You’ll see these in uppercase or lowercase form.

By combining the numbers you can make other numbers. One way to do so is by placing a smaller number in front of a larger number. The effect is similar to subtraction:

iv = 4 (think 5-1)
xl = 40 (think 50-10)

On the other hand, if you place the smaller number after the larger number then you’re adding the two:

vii = 7 (think 5+2)
lxxxii = 82 (think 50+30+2)

You can also combine these two methods:

xcii = 92 (100-10+2)

There are a few more rules for adding and subtracting, but hopefully this clarifies the basic principles.