It is known as decimal point to the sign which is used to perform the separation between the whole part and the fractional part of a number Currently, not only a point to separate both parts, but you can also use the coma . That's why people usually talk about decimal separator and not specifically of decimal point.
History shows that the first time the decimal point is mentioned is in a publication of 1492 . Almost a century later, a mathematician proposed the use of comma as a decimal separator.
Over the years, the use of the decimal point or the comma became more or less popular according to the region . Even centuries ago, other symbols were suggested to separate between the entire part and the fractional part of a figure, although they did not prosper.
It is important to establish that, in particular, it is since 2003 when the comma and period are used interchangeably. However, before the International System of Units (SI) advocated and recommended that the comma be used.
The result of this norm is that in each country one chooses to use them without any distinction or that more or less one or another is advocated. Thus, for example, among the nations that opt for the decimal point are Germany, Brazil, Spain, Argentina, France, Sweden, Russia, Italy, Greece, Switzerland or Poland, among others.
On the other hand, among the countries that prefer the decimal point are China, the United States, Japan, Mexico, the United Kingdom, India, Guatemala, the Philippines or Australia, for example.
The result of all this is that we can establish, as a general rule, that in English-speaking countries the decimal point is used while in South America and continental Europe the decimal point is chosen.
In the work "Spelling of the Spanish Language", however, we come across the fact that the use of the said decimal point is recommended for a simple reason. Which? Going to the unification of this job as a sign to separate decimals. However, make it clear of course that the comma is also correct. Thus, it states that both 11.5 and 11.5 would be well expressed.
In computer programs that work with numerical data, as it would be the case of Excel, as a rule the decimal points are used. However, people who want to replace those with commas can do so.
Suppose we want to write that a recipe to make bread requires the use of 1500 grams of flour . This is equivalent to a kilo and a half of flour or, in other words, to 1½ kilo Of flour.
If we express that amount in another way, we would say that the recipe in question carries 1.5 kilos of flour or 1.5 kilos Of flour. As you can see, the decimal point separates the numbers 1 and 5 , being 1 the whole and 5 the fractional part.
The same recipe indicates that you have to use 250 milliliters from oil . That amount is equivalent to ¼ or 0.25 liters , where the decimal point allows to separate between the integer (0 ) and the fractional part (25 ).