Inspiration
Whenever the equals sign ‘=’ is written, a word of thanks should be said for the Welsh physician and mathematician Robert Recorde (15121558).
Recorde was born in Tenby, Pembrokeshire, Wales. He took his Doctor of Medicine degree in 1545 at Cambridge, but spent much of his time prior to the M.D. and afterwards, publically teaching mathematics at Oxford.
Through his life, Recorde wrote many elementary textbooks for students. He wrote about, among other things, arithmetic and algebra, Euclid’s Elements and the astronomy of Ptolemy. But, the work for which he is perhaps most often remembered has the title The Whetstone of Witte. It was published in 1557.
In that book, he introduces the symbol we used today for equality. He explained his use of the sign ‘=’ by saying: because noe 2 thynges can be moare equalle.
In a deliberate play on words, Recorde named his book The Whetstone of Witte because it was an algebra book that sharpened a student’s mathematical wit. The Latin word “Cossa” had been used by the early European algebraists to indicate the unknown. Indeed, the study of algebra itself was originally called the Cossic art, and the Latin cos meant ‘whetstone’, a sharpening tool for knives and razors.
The story of the demise of Robert Recorde is a sad one. He died poor and in debt in 1558 at the age of 46, in the King’s Bench prison after being sued for defamation by a political enemy.
Our book is named Mathematical Whetstones in homage to Recorde. Robert Recorde dedicated a lot of his short life to the teaching of mathematics to others and wrote with the specific intention of developing ideas in a stepbystep manner. Not only did he have a deep understanding of pedagogy, but he also wrote his books in English so that learning mathematics was available to everyone, not just to the educated elite.
Recorde was born in Tenby, Pembrokeshire, Wales. He took his Doctor of Medicine degree in 1545 at Cambridge, but spent much of his time prior to the M.D. and afterwards, publically teaching mathematics at Oxford.
Through his life, Recorde wrote many elementary textbooks for students. He wrote about, among other things, arithmetic and algebra, Euclid’s Elements and the astronomy of Ptolemy. But, the work for which he is perhaps most often remembered has the title The Whetstone of Witte. It was published in 1557.
In that book, he introduces the symbol we used today for equality. He explained his use of the sign ‘=’ by saying: because noe 2 thynges can be moare equalle.
In a deliberate play on words, Recorde named his book The Whetstone of Witte because it was an algebra book that sharpened a student’s mathematical wit. The Latin word “Cossa” had been used by the early European algebraists to indicate the unknown. Indeed, the study of algebra itself was originally called the Cossic art, and the Latin cos meant ‘whetstone’, a sharpening tool for knives and razors.
The story of the demise of Robert Recorde is a sad one. He died poor and in debt in 1558 at the age of 46, in the King’s Bench prison after being sued for defamation by a political enemy.
Our book is named Mathematical Whetstones in homage to Recorde. Robert Recorde dedicated a lot of his short life to the teaching of mathematics to others and wrote with the specific intention of developing ideas in a stepbystep manner. Not only did he have a deep understanding of pedagogy, but he also wrote his books in English so that learning mathematics was available to everyone, not just to the educated elite.





