# How to determine the century?

Now is the 21st (21st) century courtyard according to the Gregorian calendar adopted in Russia. How to calculate it? How do you determine the age of the date. What calculations for this must be done, knowing that a century is a period of time equal to a hundred years? And how to determine the age most easily?

To determine the century by year, you can divide its number by 100 and add one to the whole part of the result. If the remainder turned out to be zero, then the unit does not need to be added. For example,

- 2014: 2014: 100 = 20 (remainder 14); 20 + 1 = 21 - we get the 21st century.
- 1721: 1721: 100 = 17 (remainder 21); 17 + 1 = 18 - we get the 18th century.
- 1000 year: 1000: 100 = 10 (remainder 0); since the remainder is 0, we do not add one, and we get the 10th century.

Thus, it turns out that the 20th century ended on December 31, 2000, and the 21st century began on January 1, 2001.

Determine which century or century you can and without division. It is enough to mentally discard the last two digits of the year number and add one to the number received. Again, if the dropped digits are two zeros, then you do not need to add one. For example,

- 345 year: discarding 4 and 5, 3 remains; 3 + 1 = 4 - 4th century.
- 1900: we drop two zeros, 19 remains, we don’t add one - 19th century.

We add that if the date is calculated before our era, then the century is determined in the same way as for our era, with the indication BC. er (BC). For example,

- 450 year BC e .: discarding 5 and 0, and to the remaining 4 add 1 and we get the 5th century BC. er

It must be remembered that in Russian the number of the century is usually denoted by Roman numerals, in particular, the 17th century - the 17th century, the 20th century - the 20th century.