10 (ten) is an even natural number following 9 and preceding 11.
Ten is a composite number
, its proper divisors
being 1, 2 and 5. Ten is the smallest noncototient
, a number that can not be expressed as the difference between any integer and the total number of coprimes
Ten is the second discrete biprime (2.5) and the second member of the (2.q) discrete biprime family. Ten has an aliquot sum σ(n) of 8 and is accordingly the first discrete biprime to be in deficit. All subsequent discrete biprimes are in deficit. The aliquot sequence for 10 comprises five members (10,8,7,1,0) with this number being the second composite member of the 7-aliquot tree.
It is the aliquot sum of only one number the discrete biprime 14.
Ten is a semi-meandric number.
Ten is the sum of the first three prime numbers and also of the first four factorials. Ten is the eighth Perrin number, preceded in the sequence by 5, 5, 7.
Ten squared equals 100.
A polygon with ten sides is a decagon, and 10 is a decagonal number. But it is also a triangular number and a centered triangular number.
Ten is the number of n-Queens Problem solutions for n = 5.
In numeral systems
Ten is the base of the decimal numeral system
, by far the most common system of denoting numbers
in both spoken and written language. Ten is the first two-digit number in decimal and thus the lowest number where the position of a numeral affects its value. Any integer written in the decimal system can be multiplied by ten by adding a zero to the end (e.g. 855 * 10 = 8550). The reason for the choice of ten is assumed to be that humans have ten fingers (digits).
The digit '1' followed by '0' is how the value of p is written in base p. (E.g. 16 in hexadecimal is 10.)
The Roman numeral for ten is X (which looks like two V's [the Roman numeral for 5] put together); it is thought that the V for five is derived from an open hand (five digits displayed). The Chinese word numeral for ten is 十, which resembles a cross.
Ten is a Harshad number in bases 2, 3, 5, 6, 9 and all others above.
List of basic calculations
- The interval of a major or minor tenth is an octave plus a major or minor third.
- The title of quite a few albums, including recordings by Pearl Jam and LL Cool J. See Ten (album).
- In rugby union the fly-half wears the 10 shirt.
- In blackjack, the Ten, Jack, Queen and King are all worth 10 points.
- In ten-pin bowling 10 pins are arranged in a triangular pattern and there are 10 frames per game.
- In football (soccer), the jersey number of many of the best players, particularly attacking midfielders, especially players from South America. Football legend Pelé instilled great prestige in the number in the 1960s and 70s. Other legends to have worn the number are Michel Platini, Zico, Diego Maradona, Lothar Matthäus, Gary Lineker, Roberto Baggio, Zinedine Zidane, Rivaldo, Ronaldinho, Dennis Bergkamp, Michael Owen, Juan Román Riquelme, Rui Costa, Francesco Totti, Denis Law, Gheorghe Hagi, Zvonimir Boban, William Gallas, Zlatan Ibrahimovic, and Michelle Akers, Wayne Rooney (the shirt was also worn by David Beckham during the 1996/97 season). For the 2002 World Cup Argentina requested to have the number 10 'retired' from their squad list and replaced by 24 in honour of Diego Maradona. FIFA rejected this request saying that Argentina could only leave 10 off the squad list if they intended to enter a squad of 22 players rather than the permitted 23. Argentina decided to bring 23 players to Japan & Korea with Ariel Ortega given the coveted 10. 'Number 10' player is most often used as a synonym for the team's playmaker.
- The highest score possible in Olympics competitions.
- In cricket, 10 is the number of wickets required to be taken by the bowling side for the batting side to be bowled out
- In Australian rules football, considered the break even amount of games won in a regular 22 game season, especially by Richmond coach Terry Wallace.
- In Baseball there are always at least 10 players on the field at a time (including the batter).
- The number of Baseball Hall of Famer and former New York Yankees Shortstop Phil Rizzuto
- The number of the Boston Red Sox amazing center fielder Coco(Corvellie)Crisp.
- The NASCAR car number of Scott Riggs
- Eli Manning New York Giants wears #10
- Brady Quinn Cleveland Browns wears #10
- Vince Young Tennessee Titans Wears #10
- Minimum age at which can watch a TV-PG show without parental consent.
- Minimum age at which can watch a 10-rated show or movie in Brazil without parental consent.
- Minimum age at which can rent, buy or play a E10+ rated game by the ESRB without parental consent.
In other fields
- Number of incarnations of The Doctor in the BBC science fiction television program Doctor Who
- Increasing a quantity by one order of magnitude is most widely understood to mean multiplying the quantity by ten.
- The number of theatrical Star Trek films that have been released so far.
- A collection of ten items (most often ten years) is called a decade.
- A decapod crustacean has ten limbs.
- To reduce something by one-tenth is to decimate. (In ancient Rome, the killing of one in ten soldiers in a cohort was the punishment for cowardice or mutiny; or, one-tenth of the able-bodied men in a village as a form of retribution, thus causing a labor shortage and threat of starvation in agrarian societies.)
- With ten being the base of the decimal system, a scale of 1 to 10 is often used to rank things, as a smaller version of a 1-to-100 scale (as is used in percentages and wine-tasting).
- Blake Edwards' 1979 movie 10.
- Something that scores perfectly is "a perfect ten". A person who is attractive and physically flawless is often said to be "a ten", from the idea of ranking that person's appearance and sex-appeal on a 1-to-10 scale. For example, in the movie 10 Bo Derek is supposedly a "10" on that scale.
- Counting from one to ten before speaking is often done in order to cool one's temper.
- In astrology, Capricorn is the 10th astrological sign of the Zodiac.
- In Chinese astrology, the 10 Heavenly Stems, refer to a cyclic number system that is used also for time reckoning.
- The ordinal adjective is denary.
- An online show hosted by Microsoft.
- Ben 10 is a show about a boy that can transform into 10 aliens.
- A 1977 short documentary film Powers of Ten depicts the relative scale of the Universe in factors of ten (orders of magnitude).
- CBS has a game show called Power of 10, where the player's prize goes up and down by either the previous or next power of ten.
- There are ten official inkblots in the Rorschach inkblot test.
- The traditional Snellen chart uses 10 different letters.
, 10 B.C.