👉 In mathematics, an irrational number is a real number that cannot be expressed as a simple fraction of two integers. This means that it cannot be written in the form of a ratio, such as 2/3 or π/4, where both the numerator and denominator are whole numbers. For example, the square root of 2 (which can also be written as sqrt(2)), is an irrational number because it cannot be expressed as a simple fraction. Similarly, pi (π), which is