Irrational number, that is, the real number that is not a rational number, cannot be written as the ratio of two integer numbers. If we write it as a small number formality, there are infinitely many numbers after the small number point, and it doesn't cycle. Common irrational numbers include incomplete square number square radical, π, and e (both of which are transcendental numbers). Another characteristic of the irrational number is the infinite continuous-point expression. According to legend, the irrational number was first discovered by the Pythagorean disciple Hebers.

Irrational number refers to the number that cannot be expressed as the ratio of two integer numbers in the real number range. Simply put, an irrational number is an infinite non-cyclic small number in base 10. Such as PI, √2 (radical sign 2) and so on. Rational numbers are made up of all points, integer numbers, which can be turned into finitely small numbers, or infinitely cyclic small numbers. Such as 22/7, etc.