Table number:

Number Roman number
1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
11 XI
12 XII
13 XIII
14 XIV
15 XV
16 XVI
17 XVII
18 XVIII
19 XIX
20 XX
21 XXI
22 XXII

The Symbols
The Roman numeral system uses only seven symbols: I, V, X, L, C, D, and M. I represents the number 1, V represents 5, X is 10, L is 50, C is 100, D is 500, and M is 1,000.

You can add numbers together by putting the symbols in descending order from left to right. You’d add all of the symbols’ individual values together to get the total value. For example, XVI is 10 + 5 + 1, or 16. XXXIII is 10 + 10 + 10 + 1 + 1 + 1, or 33.

You can also subtract numbers from each other by placing a symbol with a smaller value to the left of one with a larger value. The value of the smaller symbol is subtracted from that of the larger symbol to get the total value, so IV is 5 – 1, or 4.

The subtractive principle has a few specific limitations. For instance, a numeral can only be placed in front of the two numerals that are closest to it in the Roman numeral system. That is, I can only be placed before V ( e.g. IV, or 4) and X (e.g. IX, or 9). It can’t be placed before L, C, D, or M. For example, in Roman numerals, 49 would be XLIX (50 – 10 = 40 and 10 – 1 = 9), not IL. Further, you can only place one smaller numeral in front of a larger one for subtractive purposes. For example, the correct way to write 8 is VIII, not IIX.

Use a bar over each symbol to multiply it by 1,000. For example, an X with a line over it is 10,000, while an M with a line over it means 1,000,000.