Multiplication was written as M by Michael Stifel (1545),and as in by Viete (1591);our current notation dates back to William Oughtred (1637) for the symbol x,and to Wilhelm Leibniz (1698)for the dot. The symbol used by Michel Recorde (1557)came to replace the symbol used by Descartes,an a written backward,toward the end of the 17th century,thanks to Leibniz. Albert Girard (1595-1632)introduced the notation v3,which he substituted for he also introduced the abbreviations for sine and tangent, and used the symbols <,like Harriot. The symbol was introduced by Leonhard Euler (1707-1783) These notations passed into general usage only during the 19th century. 7Multiplication was written as M by Michael Stifel (1545), and as in by Vi`ete (1591); our current notation dates back to William Oughtred (1637) for the symbol ×, and to Wilhelm Leibniz (1698) for the dot. The symbol = used by Michel Recorde (1557) came to replace the symbol used by Descartes, an α written backward, toward the end of the 17th century, thanks to Leibniz. Albert Girard (1595-1632) introduced the notation √ 3, which he substituted for 1°3 ; he also introduced the abbreviations for sine and tangent, and used the symbols <, > like Harriot. The symbol P was introduced by Leonhard Euler (1707-1783). These notations passed into general usage only during the 19th century. 7