You don't need to be in Rome to do everything the Romans do. Learn to convert Roman numerals like one of the natives.

## How to Read Roman Numerals

Understand that the Roman numerals I, V, X, L, C, D and M represent the values 1, 5, 10, 50, 100, 500 and 1,000, respectively.

Add the two numerals together if a numeral is followed by one of equal or lower value. Thus, read II as "I + I," or "1 + 1," which equals 2; read VI as "V + I," or "5 + 1," which equals 6.

## Sciencing Video Vault

Subtract the first numeral from the second if a numeral is followed by one of a higher value. Thus, read IV as "1 less than 5," which is 4.

When reading larger numbers, distinguish the subtracted numbers (see step 3) before adding up the values. Example: DCXLIX = D + C + XL + IX = 500 + 100 + 40 + 9 = 649.

## How to Write Roman Numerals

Break down the number into its basic components, beginning with the largest number. Example: 273 = 200 + 70 + 3.

Break down the numbers again, using your basic values (see step 1): (200) + (70) + (3) = (100 + 100) + (50 + 10 + 10) + (1 + 1 + 1).

Convert into the appropriate Roman numerals: (C + C) + (L + X + X) + (I+ I + I) = CCLXXIII). If you have more than 3 numbers in a row, keep the first numeral and subtract accordingly. Example: 400 = 100 + 100 + 100 + 100 = "100 less than 500" = CD, instead of CCCC.

#### Tip

One caveat to reading Roman numerals: Clocks and watches usually have IIII instead of IV for four.