The equals sign or equal sign, also known as the equality sign, is the mathematical symbol =, which is used to indicate equality in some well-defined sense. In an equation, it is placed between two expressions that have the same value, or for which one studies the conditions under which they have the same value.
Recorde's introduction of "="
Robert Recorde was a Welsh physician and mathematician. He invented the equals sign (=) and also introduced the pre-existing plus (+) and minus (−) signs to English speakers in 1557.
Robert Recorde (c.1512–1558)
Recorde's introduction of the equals sign in The Whetstone of Witte, "to avoid tedious repetition".