What is called an irrational decimal?

Answer 1

An irrational number is a real number which can not be expressed in rational form, i.e. in form of a common fraction. If written in decimal form, an irrational number will contain an infinite number of decimal positions without any periodic repetition. Common examples of Irrational Numbers are Pi (3.14159...), e (2.71828...) and any non perfect root as for example, the square root of 2 (1.41421...), the square root of 7 (2.64575...), and so on. Any real number which does not fall into the the irrational number subset, must be a rational number. The rational number thus are real numbers which can be expressed in rational form, this means as the division of two integers (remembering that you can not divide into o). A rational number written in decimal form either will have a finite number of decimal positions or an infinite numbers with a periodic repetition. For example, 0.5 is a rational number because it can be written as (1/2). Another example is 1.5 which can be written as (3/2). Any integer is a rational number because it can be written as the integer divided by 1 or by any other integer, for instance, 8 = (8/1) = (16/2) = (32/4) and so on. Example of infinite periodic decimals are for instance (1/3) = 0.3333...., (4/9) = 0.4444..., (168/999) = 0.168168168...