Throwback Fact: The Equals Symbol

For this week Throwback Fact we decided to investigate the origins of the equals symbol. You may be surprised, the equals symbols hasn't been around for as long as you may think.

Where did the equals symbol come from?

First Use:

The first recorded use of the equals symbol
Source: commons.wikimedia.org

The first recorded use of the equals symbol was in 1557 by Welsh mathematician Robert Recorde. He used the symbol in his book The Whetstone of Witte to avoid having to write, “is equal to” over and over again. He used two parallel lines to represent equality because parallel lines are always equal. The symbol did not catch on right away, and it took until the 1700s for mathematicians to start using it. Now, the equals symbol is one of the most recognized algebraic symbols in the world, and has been universally accepted as being the sign for equality.

Robert Recorde (1512-1558)
Source: commons.wikimedia.org

About Robert Recorde:
Robert Recorde was born in Tenby, Wales in 1510 and graduated with a medical degree from Cambridge. Recorde served as physician to King Edward VI and Queen Mary, but his true passion was in mathematics. Recorde was the first person to write an original arithmetic book in English, rather then Latin or Greek, which made it easy for ordinary people to understand. Sadly Recorde died in 1558 in the King's Prison after being arrested for debt but still made significant contributions to English mathematics in the time he was alive. 

Source: 1, 2

Can you imagine a world without the equals symbol?