Irrational - GCSE Maths Definition

In GCSE Maths, the term "irrational" refers to numbers that cannot be written as a simple fraction, meaning they cannot be expressed as a ratio of two integers, where an integer is a whole number. These numbers have decimal parts that go on forever without repeating.

An example of an irrational number is the square root of 2, which is about 1.4142135... The most famous irrational number is pi (π), which is roughly 3.14159... . Unlike rational numbers, which either terminate or have precise, predictable decimal patterns, irrational numbers have completely random and endless sequences after the decimal point.