He adjective decimal It can be applied with reference to that which is one of the ten identical parts into which something is divided. The term is often used in the field of mathematics .
It is called decimal system to one that is formed by units that are divisors or multiples of ten with respect to the main unit of the class. He decimal numbering system , in this framework, is based on the use of quantities represented by the powers of number ten as a base.
The symbols which employs the decimal numbering system are 0 , 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and 9 . This system is positional : The value of the digit is linked to the position it occupies in the figure.
Let's see below how we should interpret in a number belonging to the decimal system the position of each of its figures. First, we must remember that we learn to name the numbers mentioned in the previous paragraph as independent elements of a number, and from our basic education we are focused on the decimal system; we call the symbol "four" 4, for example, without thinking that in the number 421 it is no longer read in this way, but "four hundred".
Continuing in the decimal system, if we begin to analyze a integer numbers from its right end, we will find the following positions or columns: units, tens, hundreds, units of thousands, tens of thousands, hundreds of thousands, units of millions and so on.
As explained in a previous paragraph, to find each of these values it is necessary to multiply a number by ten raised to a different power; in the column of the units, said power is zero, and it increases by one unit as we move to the left (thousand units, for example, are obtained by multiplying the corresponding number by ten raised to the three).
The need to classify the numbers of numbers greater than or equal to ten in different categories, so to speak, it is far from being an arbitrary or merely aesthetic issue: thanks to this division into groups it becomes much easier to resolve operations arithmetic, both the simplest and the most complex.
Only by observing the steps we take to solve a simple sum can we appreciate the comfort offered by the recognition of different positions or columns within the decimal system. If we add 4 plus 7, for example, as the result is greater than 9 we must break it down in the column of the units (where we will place a 1) and in the tens (where another will go 1).
A decimal number it is one that has an entire part and a fractional part, separated from each other by a coma (, ) or for a point (. ). The number 5,8 , for example, has a whole part (5 ) and a fractional or decimal part (0,8 ).
It should be noted that the symbol used to mark the separation between the fractional part and the entire part is known as decimal separator . In some countries, the decimal symbol is the comma, while in others the point . In this way, the number 5,8 can be written 5.8 In some regions.
Decimal numbers also have their own system of nomenclature , which gives each position a different name. With respect to the figures to the left of the comma (or the corresponding decimal separator, depending on the region), the same labels mentioned above are used; the positions that are located to the right, however, are called tenths, hundredths, thousandths, and so on.
He metric system , on the other hand, is a system of measures and weights, with the kilogram and the meter as base units, whose units are divisors or multiples of ten.