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13th Root
Extracting the 13th root of a number is a famous category for the mental calculation world records. The challenge consists of being given a large number (possibly over 100 digits) and asked to return the number that, when taken to the 13th power, equals the given number. For example, the 13th root of 8,192 is 2 and the 13th root of 96,889,010,407 is 7. Properties of the challenge Extracting the 13 th root has certain properties. One is that the 13th root of a number is much smaller: a 13th root will have approximately 1/13th the number of digits. Thus, the 13th root of a 100-digit number only has 8 digits and the 13th root of a 200-digit number will have 16 digits. Furthermore, the last digit of the 13th root is always the same as the last digit of the power. For the 13th root of a 100-digit number there are 7,992,563 possibilities, in the range 41,246,264 – 49,238,826. This is considered a relatively easy calculation. There are 393,544,396,177,593 possibilities, in the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mental Calculation
Mental calculation consists of arithmetical calculations using only the human brain, with no help from any supplies (such as pencil and paper) or devices such as a calculator. People may use mental calculation when computing tools are not available, when it is faster than other means of calculation (such as conventional educational institution methods), or even in a competitive context. Mental calculation often involves the use of specific techniques devised for specific types of problems. People with unusually high ability to perform mental calculations are called mental calculators or ''lightning calculator''s. Many of these techniques take advantage of or rely on the decimal numeral system. Usually, the choice of radix is what determines which method or methods to use. Methods and techniques Casting out nines After applying an arithmetic operation to two operands and getting a result, the following procedure can be used to improve confidence in the correctness of result: # ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Records
A world record is usually the best global and most important performance that is ever recorded and officially verified in a specific skill, sport, or other kind of activity. The book ''Guinness World Records'' and other world records organizations collates and publishes notable records of many. One of them is the World Records Union that is the unique world records register organization recognized by the Council of the Notariats of the European Union. Terminology In the United States, the form World's Record was formerly more common. The term The World's Best was also briefly in use. The latter term is still used in athletics events, including track and field and road running to describe good and bad performances that are not recognized as an official world record: either because it is not an event where the IAAF tracks the record (e.g. the 150 m run or individual events in a decathlon), or because it does not fulfill other rigorous criteria of an otherwise qualifying event (e.g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nth Root
In mathematics, a radicand, also known as an nth root, of a number ''x'' is a number ''r'' which, when raised to the power ''n'', yields ''x'': :r^n = x, where ''n'' is a positive integer, sometimes called the ''degree'' of the root. A root of degree 2 is called a ''square root'' and a root of degree 3, a ''cube root''. Roots of higher degree are referred by using ordinal numbers, as in ''fourth root'', ''twentieth root'', etc. The computation of an th root is a root extraction. For example, 3 is a square root of 9, since 3 = 9, and −3 is also a square root of 9, since (−3) = 9. Any non-zero number considered as a complex number has different complex th roots, including the real ones (at most two). The th root of 0 is zero for all positive integers , since . In particular, if is even and is a positive real number, one of its th roots is real and positive, one is negative, and the others (when ) are non-real complex numbers; if is even and is a negative real numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guinness Book Of World Records
''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world records both of human achievements and the extremes of the natural world. The brainchild of Sir Hugh Beaver, the book was co-founded by twin brothers Norris and Ross McWhirter in Fleet Street, London, in August 1955. The first edition topped the best-seller list in the United Kingdom by Christmas 1955. The following year the book was launched internationally, and as of the 2022 edition, it is now in its 67th year of publication, published in 100 countries and 23 languages, and maintains over 53,000 records in its database. The international franchise has extended beyond print to include television series and museums. The popularity of the franchise has resulted in ''Guinness World Records'' becoming the primary international authority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexis Lemaire
Alexis Lemaire (born 1980) is a mental calculation world record holder. He holds a Ph.D. in Computer Science related to artificial intelligence from the University of Reims. He is also the owner of world records for mentally calculating the 13th root of 100-digit numbers and 200-digit numbers. On 10 May 2002, he calculated the 13th root of a 100-digit number in 13.55 seconds, beating the record held by Willem Klein (88.8 seconds) and the somewhat less official record of Gert Mittring Gert Mittring (born May 26, 1966 in Stuttgart) is a German mental calculator. He was inspired by the late Wim Klein. He has competed in the MSO mental calculation event every year since 2004, failing to win the gold medal outright on only four ... (39 seconds). On 23 November 2004, Mittring tried to beat Lemaire's record, but his time of 11.8 seconds was not counted as official, as one organization's rules had decided to stop recognizing records for root extraction of random numbers due to the dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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