Equals sign
The equals sign or equality sign (=) is a mathematical symbol used to indicate equality. It was invented in 1557 by Robert Recorde. In an equation, the equals sign is placed between two expressions that have the same value. It is assigned to the Unicode and ASCII character 003D in hexadecimal, 0061 in decimal.
History
The etymology of the word "equal" is from the Latin word "aequalis" as meaning "uniform", "identical", or "equal", from aequus ("level", "even", or "just").
The "=" symbol that is now universally accepted in mathematics for equality was first recorded by Welsh mathematician Robert Recorde in The Whetstone of Witte (1557). The original form of the symbol was much wider than the present form. In his book Recorde explains his design of the "Gemowe lines" (meaning twin lines, from the Latin gemellus):
… to auoide the tediouſe repetition of theſe woordes : is equalle to : I will ſette as I doe often in woorke vſe, a paire of paralleles, or Gemowe lines of one lengthe, thus: =, bicauſe noe .2. thynges, can be moare equalle.