The origin of the numbers is very old and arose by the necessity that had the man to count.
Getting to write the numbers as we do now it was not far from easy.
At first, they counted on the fingers, with stones, doing wood marks or knots in a cord.
Almost all the systems of the old civilizations represented small numbers well, but it was very difficult to them to do it with the
great amounts because they had to put so many symbols that were very little practical.
The system that we used, DECIMAL SYSTEM, was invented by the Indians and brought to Europe by the Arabs. Its great success consisted of introducing
the symbol of the zero, that allows just by ten symbols, to represent any number by great that is .
Decimal Numbering System
Besides the zero, another very important innovation of our system of numeration it is that each number or digit
has a value according to the place that occupies.
It is necessary to know very clearly what they which means the concept of Units, Tens, Hundreds and to know the value that represents.
Units: First number beginning by the right; its value is the one of the digit that occupies that place.
Tens: Second number beginning by the right. Each ten is 10 units, therefore, its value is the one of the digit that occupies that place multiplied by 10.
Hundreds: Third number beginning by the right. Each hundred is 100 units, therefore, its value is the one of the digit that occupies that place multiplied by 100.
The numbers can be written with numbers or letters. In order to write them with letters we will consider the following criteria:
The units are written with the name of the digit that represent: one, two, three, four, five, six, seven, eight and nine.
The tens, generally, finish in -ty: twenty, thirty, seventy, ninety ... except in the case of the ten, that has an irregular writing:
Eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen and nineteen.
The hundreds finish in hundred: one hundred, two hundred, three hundred ...
In order to read a number with many digits, first that we will do it will be to separate groups of three numbers, from right to left.
Traditionally, the notation that is used for its reading is the following one:
After the first group we put a dot (.) that reads thousand, after the second group we put a
(1) that reads million, after the third group we return to put a dot (.), after the fourth group we put a (2)
and thus we would follow until all the numbers are finished. Its value is:
The Pan-Hispanic Dictionary of doubt says: "The international norm establishes that it is done without the point to separate thousands, millions, etc. ...
In order to facilitate the reading of the numbers that they have more than four numbers it recommends to separate these by means of spaces in groups of three, counting from right to left.
This recommendation does not have to be applied in countable documents nor in the writings in which the separation would risk its safety."