Oughtred, William

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English mathematician, credited as the inventor of the slide rule in 1622. His major work Clavis mathematicae/The Key to Mathematics (1631) was a survey of the entire body of mathematical knowledge of his day. It introduced the ‘×’ symbol for multiplication, as well as the abbreviations ‘sin’ for sine and ‘cos’ for cosine.

The stars are said to represent Syria and Iraq. Red, white, black, and green are the pan-Arab colours. Effective date: 29 March 1980. >>