We've already looked at the London Welshman who invented the pi symbol; today, we've another London Welsh mathematician who invented the 'equals' symbol.
Robert Recorde was born in 1510 in Tenby, and went to Oxford University in 1525. Having taught maths there for a while, he went on to Cambridge to qualify as a doctor before moving to London. There, he was physician to Edward VI and controller of the Royal Mint. Among his publications was The Urinal of Physick, which sounds disrespectful but was actually a guide to the then-mainstream practice of making diagnoses by inspecting the patient's urine. In 1558, though, he would die in debtors' prison after being sued for libel by his enemy, the hugely powerful Earl of Pembroke.
Only a year earlier, he had published the snappily-titled The Whetstone of Witte, whiche is the seconde parte of Arithmeteke: containing the extraction of rootes; the cossike practise, with the rule of equation; and the workes of Surde Nombers. Whatever the shortcomings in the name of the book, the contents contained one amazing innovation: the introduction of the equals sign.
How did mathematicians manage before this invention? By writing the word, often in Latin, or using one's own choice of abbreviation such as aeq. How much easier it is to draw two quick lines - something for which we have to thank Robert Recorde. Even ardent Scrabble enthusiasts, however, probably don't thank him for his other invention: zenzizenzizenzic,* the English word with the most zs!
* Zenzizenzizenzic = the 8th power of a number. It's useless for Scrabble, which has only one Z and two blanks!
Robert Recorde was born in 1510 in Tenby, and went to Oxford University in 1525. Having taught maths there for a while, he went on to Cambridge to qualify as a doctor before moving to London. There, he was physician to Edward VI and controller of the Royal Mint. Among his publications was The Urinal of Physick, which sounds disrespectful but was actually a guide to the then-mainstream practice of making diagnoses by inspecting the patient's urine. In 1558, though, he would die in debtors' prison after being sued for libel by his enemy, the hugely powerful Earl of Pembroke.
Only a year earlier, he had published the snappily-titled The Whetstone of Witte, whiche is the seconde parte of Arithmeteke: containing the extraction of rootes; the cossike practise, with the rule of equation; and the workes of Surde Nombers. Whatever the shortcomings in the name of the book, the contents contained one amazing innovation: the introduction of the equals sign.
How did mathematicians manage before this invention? By writing the word, often in Latin, or using one's own choice of abbreviation such as aeq. How much easier it is to draw two quick lines - something for which we have to thank Robert Recorde. Even ardent Scrabble enthusiasts, however, probably don't thank him for his other invention: zenzizenzizenzic,* the English word with the most zs!
* Zenzizenzizenzic = the 8th power of a number. It's useless for Scrabble, which has only one Z and two blanks!