Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Irrational numbers are numbers that cannot be expressed as the ratio of two whole numbers. This is opposed to rational numbers, like 2, 7, one-fifth and -13/9, which can be, and are, expressed as the ...

Originally defined as the ratio between the circumference of a circle and its diameter, pi — written as the Greek letter π — ...

A recurring decimal exists when decimal numbers repeat forever. For example, \(0. \dot{3}\) means 0.333333... - the decimal never ends. Dot notation is used with recurring decimals. The dot above the ...