When determining the ordinal century can encounter two difficulties.

The first is to mark the century adopted Roman numerals, but not all know how to read them correctly. To deal with Roman numerals will follow the sign matching the signs in the Roman notation of the number of Arab cmfrom:

X – 10

V – 5

I - 1
Further all is simple: add up all the tens (X) and five (V), we add unity, located at the end record the number, subtract the ones located elsewhere.

For example:

XIX – two dozen and one unity is not the end of the recording, i.e. 10 + 10 – 1 = 19 – marking of the nineteenth century;

XIV – a dozen one, five, one and one unity is not the end of the recording, i.e. 10 + 5 – 1 = 14 – a designation of the fourteenth century;

XVII – dozen one, one five and two ones at the end of the record, i.e. 10 + 5 + 1 + 1 = 17 – marking the seventeenth century.
The second point that must be remembered when determining century that the Arab record numbers the last two digits of the year number and the previous number of the century, the century number is one more meaning of the number.


1932 – century significance of the numbers 19, therefore, the twentieth century;

345 room (ages 3, therefore, the fourth century.