The concept of a decade in the modern world is not common, but you need to know it in order to freely navigate in time and have an idea about the duration of socially important events. A decade is a period of time that lasts ten days or ten years. From signboards and announcements, you can learn about the upcoming decade of language development, at work you can stumble upon a report on the psychology decade, and at school you can get acquainted with the analysis of the decade of the natural-mathematical cycle.
Decade is a concept known since ancient times
The word "decade" came to us from antiquity and then literally meant "ten". This concept was present in ancient culture. Later it was transferred from Latin and Greek to modern European languages. Thus, the meaning of the word "ten" has been preserved, and it is no coincidence that the word "ten" in the Russian language is consonant with "decade", a borrowing word from the Greek language.
European languages are no exception here either. Despite the difference in spelling and some differences in sound, the common Indo-European root, fromwhich the word "decade" was formed, can be identified in many modern European languages. In German ten is zehn, in English ten, in French dix.
The origin of the decade and its current usage
The Pythagoreans considered the number 10 magical and attached great importance to it. In addition, people have always understood that it is more convenient to count, taking the decimal number system as a basis.
Today it is customary to divide a month into weeks, and this division is based on the number 7. A decade is a third of a month, that is, it implies a time period of ten days. During the French Revolution, it was decided to introduce a calendar using a ten-day unit of measurement. This greatly facilitated and simplified the perception of time, because it is easier to break a month into ten units than into seven.
But still, a decade is how much: ten days or ten years? In modern Russian, a decade is most often used in the first meaning. When a decade appears in a speech, one of the three decades of a certain month is usually meant (for example, the first decade of March, the second decade of September, etc.). But in principle, such a concept as a decade of the year can also be defined. To calculate it, you need to divide the total number of days in a year (365 or 366 days) by 10, get the total number of decades (36.5 or 36.6) and select the one of interest in the year.
So, despite the relatively rare use of this unit of time, it offers some convenience for those involved in mathematics, physics,electronics, economics, operates with statistical and any other numerical data. Knowledge of the term is necessary for every person for a good orientation in the realities of the modern world.
