Topic Everything is a number Everything is a number What is number then?. Notation Thank you for Attention. - презентация

1 Topic Everything is a number Everything is a number What is number then?. Notation Thank you for Attention

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3 Numbers... they are with us everywhere and always. But in any case, the number was depicted using one or more digits. People have always counted and written down numbers, even five thousand years ago. But they wrote them down in a completely different way, according to different rules. Numbers... they are with us everywhere and always.

4 So the Pythagoreans spoke, emphasizing the unusually important role of numbers in practical activities.. "Everything is a number" A modern person remembers car and phone numbers every day, calculates the cost of purchases in a store, and keeps a family budget.... "Everything is a number"

5 Numbers are symbols that make up some alphabet. What is a number then? A number is a certain value consisting of numbers added according to certain rules. At different stages of human development, for different peoples, these rules were different and today we call them number systems.

6 - this is a sign system in which all numbers are written according to certain rules using symbols of a certain alphabet, called numbers. non-positional positional

7 So, let's consider various non-positional number systems. Non-positional number systems arose earlier than positional ones.

8 - such a number system is called, in which the quantitative equivalent ("weight") of a digit does not depend on its location in the number entry.

9 At first, people simply distinguished ONE object in front of them or not. If the subject was not one, then they said "A LOT OF" At first, people simply distinguished ONE object in front of them or not.

10 The first concepts of mathematics were "less", "greater", "the same". > < = > < = >">

11 It was enough to put a knife next to each fish for the exchange between the tribes to take place. If one tribe exchanged caught fish for stone knives made by people of another tribe, it was not necessary to count how many fish they brought and how many knives.

12 The account appeared when a person needed to inform his fellow tribesmen about the number of items he found. And, since many peoples in antiquity did not communicate with each other, different peoples had different systems of numbering and representing numbers and numbers. The account appeared when a person needed to inform his fellow tribesmen about the number of items he found.

13 The numerals in many languages indicate that the primitive man had mainly fingers as a counting tool. Fingers turned out to be an excellent calculating machine.

14 With their help, it was possible to count up to 5, and if you take two hands, then up to Decimal counting system later became common. With their help, it was possible to count up to 5, and if you take two hands, then up to 10.

15 However, peoples are known whose units of counting were not fingers, but their joints. Therefore, they could use both fingers and toes for counting. In ancient times, people walked barefoot. There are still tribes in Polynesia that use the 20th number system.

16 For example, at the world's largest grain exchange in Chicago, offers and requests, as well as prices, are announced by brokers on their fingers without a single word. Finger counting has been preserved in some places to this day

17 Появилась потребность в записи чисел. Запомнить большие числа было трудно, поэтому к «счетной машине» рук и ног стали добавлять различные приспособления. Количество предметов изображалось нанесением черточек или засечек на какой- либо твердой поверхности: камне, глине…

18 The more grain people gathered from their fields, the more numerous their herds became, the larger numbers they needed. A single notation for such numbers was cumbersome and inconvenient, so people began to look for more compact ways to denote large numbers.

19 10 in the usual decimal number system (ten fingers on the hands). Alphabet: 1, 2, 3, 4, 5, 6, 7, 8, 9, invented in ancient Babylon: dividing an hour into 60 minutes, a minute into 60 seconds, an angle into 360 degrees. 12 invented in ancient Babylon: dividing an hour into 60 minutes, a minute into 60 seconds, an angle into 360 degrees. 7 used to count the days of the week

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