# Signs of multiplication and division

**Signs of multiplication and division** played a huge role in the development of mathematics. The sign of the "oblique cross" multiplication (x) was first introduced by the English mathematician William Ouartred (1575-1660). The multiplication by a column, familiar to us from the school bench, is an invention not so far away! (His also invented Oudred.) His disciples were the famous Christopher Wren - the creator of St. Paul's Cathedral in London and the great mathematician J. Wallis. Another remarkable invention of Ottred was also the well-known logarithmic ruler, which was introduced into the wide engineering practice by the creator of the universal steam engine J. Watt at his Soho engineering plant. Later, in 1698 the German mathematician G. Leibniz introduced the multiplication symbol "point".

People learned to share numbers much later than multiply. In Babylon the division by inverse number tables was reduced to multiplication , the Egyptians used a special table of basic fractions. The European mathematician Herbert (born in 950 in Aquitaine) in his writings cited the rules division. But they were too complicated and got the name of "iron division". Later in Europe, the Arabian method of division appeared, which we still use. It was much simpler, and therefore it was called "golden division". The oldest **division sign** most likely looked like this: "/". It was first used by the English mathematician William Ouartred in his work "Clavis Mathematicae" (1631, London). The German mathematician Johan Rahn introduced the "+" sign for multiplication. He appeared in his book "Deutsche Algebra" (1659). The Sign of the Rana is often called the "English Sign", because the English were the first to use it, although its roots lie in Germany. The German mathematician Leibniz preferred the colon ":" - this symbol was first used in 1684 in his work "Acta eruditomm". Before Leibniz this sign was used by the Englishman Johnson in 1633 in one book, but as a sign of fractions, and not of division in the narrow sense. In most countries, the colon is preferred: "", in English-speaking countries and on the keys of the microcalculators the symbol "+". For mathematical formulas throughout the world, the "/" sign is preferred. Signs of multiplication and division did not immediately receive universal recognition. How slowly the most elementary symbols entered into use, shows the following fact. In 1731, Steven Helss publishes his "Etudes on Statics" a large and serious work, addressed primarily to the members of the Royal Society of London and signed by the President of the Society Isaac Newton. In the foreword to this book the author writes: "Since complaints are heard that the signs I use are not clear to many (the book was published in the second edition), I will say: the sign" + "means" more "or" add ", so on page 18, line 4: "6unts + 240 grains" means the same as saying "add 240 grains to 6 ounces," and on line 16 of the same page, the sign "x" means "multiply", two short parallel lines mean "equals", so 1820õ4 - 7280, it's like that 1820, multiplied by 4, give (equal) to 7280".

The symbols of multiplication and division (& divide;) and (:) can also be used to denote a range. For example, "5÷10" can denote a range [5, 10], that is, 5 to 10 inclusive. If there is a table whose rows are denoted by numbers and columns are denoted by Latin letters, then a record of the form "D4: F11" can be used to denote an array of cells (two-dimensional range) from D to F and from 4 to 11.