# 10 (number): Wikis

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# Encyclopedia

10
Cardinal 10
ten
Ordinal 10th
(tenth)
Numeral system decimal
Factorization $2\cdot5$
Divisors 1, 2, 5, 10
Roman numeral X
Unicode symbol(s) X, x
Greek Prefix deca-/deka-
Latin Prefix deci-
Binary 10102
Octal 128
Duodecimal A12
----
Chinese numeral 十，拾
Hebrew י (Yod)
Khmer ១០
Korean
Thai ๑๐
Hindi १०

10 (ten) (pronounced /ˈtɛn/ ( listen)) is an even natural number following 9 and preceding 11.

## In mathematics

Ten is a composite number, its proper divisors being 1, 2 and 5. Ten is the smallest noncototient, a number that cannot be expressed as the difference between any integer and the total number of coprimes below it.

Ten is the second discrete semiprime (2.5) and the second member of the (2.q) discrete semiprime family. Ten has an aliquot sum σ(n) of 8 and is accordingly the first discrete semiprime to be in deficit. All subsequent discrete semiprimes 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 semiprime 14.

Ten is a semi-meandric number.

Ten is the sum of the first three prime numbers, of the four first numbers (1 + 2 + 3 + 4), of the square of the two first odd numbers and also of the first four factorials (0! + 1! + 2! + 3!). Ten is the eighth Perrin number, preceded in the sequence by 5, 5, 7.

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.

### Counting

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Base Numeral system Number
1 unary **********
2 binary 1010
3 ternary 101
4 quaternary 22
5 quinary 20
6 senary 14
7 septenary 13
8 octal 12
9 novenary 11
10 decimal 10

Ten is a Harshad number in bases 2, 3, 5, 6, 9 and all others above.

### List of basic calculations

Multiplication 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 25 50 100 1000
$10 \times x$ 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 250 500 1000 10000
Division 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
$10 \div x$ 10 5 $3.\overline{3}$ 2.5 2 $1.\overline{6}$ $1.\overline{428571}$ 1.25 $1.\overline{1}$ 1 $0.\overline{9}\overline{0}$ $0.8\overline{3}$ $0.\overline{769230}$ $0.\overline{714285}$ $0.\overline{6}$
$x \div 10$ 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5
Exponentiation 1 2 3 4 5 6 7 8 9 10 11 12 13
$10 ^ x\,$ 10 100 1000 10000 100000 1000000 10000000 100000000 1000000000 10000000000 100000000000 1000000000000 10000000000000
$x ^ {10}\,$ 1 1024 59049 1048576 9765625 60466176 282475249 1073741824 3486784401 10000000000 25937424601 61917364224 137858491849

## In science

### Astronomy

• The Saros number of the solar eclipse series which began on -2467 February 28 and ended on -1169 April 18. The duration of Saros series 10 was 1298.1 years, and it contained 73 solar eclipses.
• The Saros number of the lunar eclipse series which began on -2454 June 17 and ended on -1138 August 15. The duration of Saros series 10 was 1316.2 years, and it contained 74 lunar eclipses.

## In sports and games

• 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 players, particularly attacking midfielders.
• 'Number 10' player is most often used as a synonym for a soccer 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.
• In Baseball there are always at least 10 players on the field at a time (including the batter).
• Driving a racing car at ten-tenths is driving as fast as possible, on the limit.

## In other fields

10 playing cards of all four suits
• Increasing a quantity by one order of magnitude is most widely understood to mean multiplying the quantity by ten.
• 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.
• 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. [2]
• 10 is in the name of the television show Ben 10
• 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.

Ten is:

## Historical years

10 A.D., 10 B.C., 1910, 2010, etc.

# Simple English

Simple English Wiktionary has the word meaning for:

Ten is the number that is after nine and before eleven. Most people have ten fingers and ten toes.

Ten is the smallest positive whole number with two digits. Ten is an important number because most people write numbers using multiples of ten. This is called the decimal number system.koi:10 (дас)