Born in the Berkshire area (England) and educated at King's College, Cambridge, I later left my studies to admit to holy orders.
Though placed in a rectory in Albury, I eventually was asked to instruct the Earl of Arundel's son in mathematics.
While corresponding with many eminent scholars, I taught mathematics to anyone (e.g. John Wallis and Christoher Wren), offering free tuition.
Extending the work of Napier and Gunter, I invented the slide-rule by juxtaposing two logarithmic scales to perform direct multiplication and division.
In my book Clavis Mathematicae, I introduced mathematical notation, such as the "x" symbol for multiplication, the proportion sign "::" and the abbreviations "sin" and "cos" for the sine and cosine functions.
As part of a priority dispute with Delamain over the invention of the slide rule, I also argued strongly with him about the best ways to teach/learn mathematics...my claim: theory should precede practice.
William Oughtred (1574 - 1660)