In which century did Robert Recorde introduce the equals sign?

Robert Recorde introduced the equals sign in the 16th century, specifically in 1557. His intention was to create a symbol that would indicate equality more clearly than the words he used previously, such as "is equal to." The equals sign is made up of two parallel horizontal lines, which Recorde believed represented a balanced state. This innovation has had a lasting impact on mathematics, as it provided a standard way to express equality that is still used today. Understanding the historical context helps emphasize the significance of Recorde's work in the evolution of mathematical notation.