Telephone communication was officially invented at the end of the 19th century. The number of telephone users at that time was small, and the subscriber numbering was limited to only four digits. Having called the switchboard, the subscriber called his number, for example "32-15", and the telephone operator made the connection. Over time, telephone communication has developed so much that it became possible to call not only within the city, but also to other countries. The telephone revolution also brought about a change in telephone numbers.
Instructions
Step 1
Now, in order to make a call to another city or to another country, it is enough to pick up the telephone receiver and, having dialed a sequence of numbers, successfully communicate. This was not always the case, and the first telephones did not have numbers and letters, but were equipped with only two tubes, one of which was responsible for receiving voice, the second was used for transmitting speech.
Step 2
Before the automatic telephone exchange was developed, communication between subscribers was carried out only through telephone operators. To communicate with the switch, it was only necessary to pick up the receiver from the telephone set. Years later, when the telephone set began to be supplied with a dial for dialing, the number "0" was used only to communicate with the operator (operator), which has survived to this day.
Step 3
Initially, telephone numbers were four digits long. With the increase in the number of subscribers, telephone numbers also changed. At the beginning of the twentieth century, there were more than 150 thousand telephone users in Russia, and in the United States in the same years already millions of people had telephones, and four-digit numbering was not enough. Over time, the number of digits in the number began to increase, and the numbers became seven-digit. Memorizing seven digits became difficult, as a result of this, the Americans simplified the numbering using a mnemonic rule that replaced the first three digits with letters - "ABC-4567", and on the rotary telephones that had already appeared at that time, along with the numbers, letters were indicated.
Step 4
In Russia, with an increase in the number of subscribers, one letter has been added to telephone numbers of four digits (for example, A-23-45). Each letter corresponded to a certain telephone exchange: "G" - Arbatskaya, "E" - Baumanskaya, "I" - Dzerzhinskaya, "V" - Kirovskaya, "D" - Miusskaya, "Zh" - Taganskaya, "K" - Central.
Step 5
Later, when new telephone exchanges appeared, numbers with two letters appeared, but from January 1, 1968, the letters were replaced by numbers: "A" became one, "G" became a four, "K" - into a nine, "E" - in six, "AB" - in 12, "AB" - in 13, etc. This numbering system existed until 1968, then all letters were replaced by numbers and numbers became six-digit, and then seven-digit.
Step 6
With the growth of telephone lines, long-distance automatic communication appeared. Each city was assigned a digital code. The code of Moscow became 095, St. Petersburg (then Leningrad) - 812, Alma-Ata - 327. By 2005, the code of Moscow was changed to 495, three years later the code 499 also appeared. From July 1, 2012, the code set 495 became mandatory, and all intercity numbers are now available only through the eight. If you want to call some city in Russia, for example, Tver, to the number 12-34-56, you will need the telephone area code of Tver (it is 4822). Dialing order: 8-4822-123456.
Step 7
With the development of international telephone lines, each country was assigned its own code, as well as the cities in this country. The number "+7" was assigned to Russia. For international communication, you need to dial the country code, area code and then the subscriber's number. For example, if you want to contact a friend from Germany, you should dial: 8-10-49 (country code) -089 (area code) -subscriber's number.
