What is the history of the equality symbol?

Question

I've been trying to find information regarding the history of the equality symbol (=). The most I've been able to find after several days of searching is
"The equal symbol (=) was first used by Robert Recorde (c. 1510-1558) in 1557 in The Whetstone of Witte. He wrote, "I will sette as I doe often in woorke use, a paire of parralles, or Gemowe lines of one lengthe, thus : ==, bicause noe 2, thynges, can be moare equalle." Recorde used an elongated form of the present symbol."
Does anyone know something more informative (for example, how people showed equality before "=" was the equality symbol) or know of a web page where I could find such information?

Answer 1

It is hard to realize that the history of mathematical equations as we know them is only 450 years old. Prior to 1557 equations were written a word problems or with separate lines of symbols. Indeed, the publishing (printing) of equations with an equal sign did not seem to catch on in popularity until after 1600.

Please remember that Leonardo Fibonacci (also called Leonardo Pisano) did not publish his "Liber Abaci" (Book of Calculation) until 1202, at which time the Hindu numerals (0 to 9) became openly used in Europe (instead of Roman numerals).

You might want to play around in MacTutor History of Mathematics, see the site below: