How to calculate:

M = 1000

CM = 1000-100 = 900

LXX = 50+10+10 = 70

IV = 5-1 = 4

--------------------------------

Total = 1974

Note: Usually, no more than three of any one symbol is used to represent a number.

- If a letter or symbol is repeated in sequence, the numbers are added.

- If a symbol for a smaller number is used after the symbol for a larger number, the numbers are added.

- If a symbol for a smaller number is used before the symbol for a larger number, the smaller number is subtracted from the greater number.

More Info: slideplayer.com