|Did you know . . .?|
The symbol '=' was first used only in 1557!
It was the invention of a Welshman named Robert Recorde, the man who first introduced algebra to England.
Recorde used the symbol, composed of two parallel lines, in his 1557 book The Whetstone of Witte to avoid having to write over and over again "is equal to."
But the symbol didn't catch on right away. Some people preferred the symbol ' ||,' while others used the abbreviation ae or oe (for the Latin aequalis or "equal") into the 1700s.
As for Recorde himself, he died a debtor in King's Bench Prison.
In his own words:
"To avoide the tediouse repetition of these woordes: is equalle to: I will settle as I doe often in woorke use, a paire of paralleles, or gemowe [twin] lines of one lengthe: =, bicause noe .2. thynges, can be moare equalle." --Robert Recorde, The Whetstone of Witte (1557).
For more information:
By Laura Smoller, UALR Department of History.