Equals sign (=)
Signo igual (=)
- Date
- 1557 · confidence high
- Place
- London, United Kingdom
- Credited to
- Robert Recorde
- Field
- Knowledge & symbols
What it is
Welsh mathematician Recorde introduced the '=' symbol, two parallel lines, in his book 'The Whetstone of Witte', reasoning that 'no two things can be more equal'; its adoption was slow until Newton and Leibniz generalised it.
The symbol took more than a century and a half to become widespread after its introduction.
What it led to
- Modern algebraic notation and its international spread
- Simplification of writing equations