# 3 (number)

 ← 2 3 4 →
Cardinalthree
Ordinal3rd
(third)
Factorizationprime
Divisors1, 3
Roman numeralIII
Roman numeral (unicode)Ⅲ, ⅲ
Greek prefixtri-
Latin prefixtre-/ter-
Binary112
Ternary103
Quaternary34
Quinary35
Senary36
Octal38
Duodecimal312
Vigesimal320
Base 36336
Arabic٣,3
Urdu
Bengali
Chinese三，弎，叁
Devanāgarī (tin)
Ge'ez
Greekγ (or Γ)
Hebrewג
Japanese
Khmer
Korean셋,삼
Malayalam
Tamil
Telugu
Thai

 ← 2 3 4 →
Cardinalthree
Ordinal3rd
(third)
Factorizationprime
Divisors1, 3
Roman numeralIII
Roman numeral (unicode)Ⅲ, ⅲ
Greek prefixtri-
Latin prefixtre-/ter-
Binary112
Ternary103
Quaternary34
Quinary35
Senary36
Octal38
Duodecimal312
Vigesimal320
Base 36336
Arabic٣,3
Urdu
Bengali
Chinese三，弎，叁
Devanāgarī (tin)
Ge'ez
Greekγ (or Γ)
Hebrewג
Japanese
Khmer
Korean셋,삼
Malayalam
Tamil
Telugu
Thai

3 (three; ) is a number, numeral, and glyph. It is the natural number following 2 and preceding 4.

## In mathematics

### In numeral systems

It is frequently noted by historians of numbers that early counting systems often relied on the three-patterned concept of "One, Two, Many" to describe counting limits. Early peoples had a word to describe the quantities of one and two, but any quantity beyond was simply denoted as "Many". As an extension to this insight, it can also be noted that early counting systems appear to have had limits at the numerals 2, 3, and 4. References to counting limits beyond these three do not appear to prevail as consistently in the historical record.

### List of basic calculations

Multiplication12345678910111213141516171819202122232425501001000
$3 \times x$369121518212427303336394245485154576063666972751503003000
Division123456789101112131415
$3 \div x$31.510.750.60.5$0.\overline{428571}$0.375$0.\overline{3}$0.3$0.\overline{27}$0.25$0.\overline{230769}$$0.2\overline{142857}$0.2
$x \div 3$$0.\overline{3}$$0.\overline{6}$1$1.\overline{3}$$1.\overline{6}$2$2.\overline{3}$$2.\overline{6}$3$3.\overline{3}$$3.\overline{6}$4$4.\overline{3}$$4.\overline{6}$5
Exponentiation12345678910111213
$3 ^ x\,$3927812437292187656119683590491771475314411594323
$x ^ 3\,$1827641252163435127291000133117282197

## Evolution of the glyph

Three is the largest number still written with as many lines as the number represents. (The Ancient Romans usually wrote 4 as IIII, but this was almost entirely replaced by the subtractive notation IV in the Middle Ages.) To this day 3 is written as three lines in Roman and Chinese numerals. This was the way the Brahmin Indians wrote it, and the Gupta made the three lines more curved. The Nagari started rotating the lines clockwise and ending each line with a slight downward stroke on the right. Eventually they made these strokes connect with the lines below, and evolved it to a character that looks very much like a modern 3 with an extra stroke at the bottom. It was the Western Ghubar Arabs who finally eliminated the extra stroke and created our modern 3. (The "extra" stroke, however, was very important to the Eastern Arabs, and they made it much larger, while rotating the strokes above to lie along a horizontal axis, and to this day Eastern Arabs write a 3 that looks like a mirrored 7 with ridges on its top line): ٣[3]

While the shape of the 3 character has an ascender in most modern typefaces, in typefaces with text figures the character usually has a descender, as, for example, in . In some French text-figure typefaces, though, it has an ascender instead of a descender.

A common variant of the digit 3 has a flat top, similar to the character Ʒ (ezh). Since this form is sometimes used to prevent people from fraudulently changing a 3 into an 8, it is sometimes called a banker's 3.

## In religion

Many world religions contain triple deities or concepts of trinity, including:

The Shield of the Trinity is a diagram of the Christian doctrine of the Trinity

### In Buddhism

• The Triple Bodhi (ways to understand the end of birth) are Budhu, Pasebudhu, and Mahaarahath.

### In Hinduism

The "Om" symbol, in Devanagari is also written ओ३म् (ō̄m [õːːm]), where ३ is दीर्घ (dirgha, "three times as long")

### In Norse mythology

Three is a very significant number in Norse mythology, along with its powers 9 and 27.

• Prior to Ragnarök, there will be three hard winters without an intervening summer, the Fimbulwinter.
• Odin endured three hardships upon the World Tree in his quest for the runes: he hanged himself, wounded himself with a spear, and suffered from hunger and thirst.
• Bor had three sons, Odin, Vili, and .

### As a lucky or unlucky number

Three (三, formal writing: 叁, pinyin sān, Cantonese: saam1) is considered a good number in Chinese culture because it sounds like the word "alive" (生 pinyin shēng, Cantonese: saang1), compared to four (四, pinyin: , Cantonese: sei1), which sounds like the word "death" (死 pinyin , Cantonese: sei2).

Counting to three is common in situations where a group of people wish to perform an action in synchrony: Now, on the count of three, everybody pull!  Assuming the counter is proceeding at a uniform rate, the first two counts are necessary to establish the rate, and the count of "three" is predicted based on the timing of the "one" and "two" before it. Three is likely used instead of some other number because it requires the minimal amount counts while setting a rate.

In Vietnam, there is a superstition that considers it bad luck to take a photo with three people in it; it is professed that the person in the middle will die soon.

There is another superstition that it is unlucky to take a third light, that is, to be the third person to light a cigarette from the same match or lighter. This superstition is sometimes asserted to have originated among soldiers in the trenches of the First World War when a sniper might see the first light, take aim on the second and fire on the third.

The phrase "Third time's the charm" refers to the superstition that after two failures in any endeavor, a third attempt is more likely to succeed. This is also sometimes seen in reverse, as in "third man [to do something, presumably forbidden] gets caught".

Luck, especially bad luck, is often said to "come in threes".[4]

## In sports

• In association footballin almost all leagues, and in the group phases of most international competitions, 3 competition points are awarded for a win.
• In Gaelic football, hurling and camogie, a "goal", with a scoring value of 3, is awarded when the attacking team legally sends the ball into the opponent's goal.
• In baseball, 3 is the number of strikes before the batter is out and the number of outs per side per inning; in scorekeeping, 3 is the position of first-baseman.
• A shot made from behind the three-point arc is worth 3 points (except in the 3x3 variant, in which it is worth 2 points).
• A potential "three-point play" exists when a player is fouled while successfully completing a two-point field goal, thus being awarded one additional free throw attempt.
• On offense, the "3-second rule" states that an offensive player cannot remain in the opponent's free throw lane for more than 3 seconds while his team is in possession of the ball and the clock is running.
• In the NBA only, the defensive 3-second violation, also known as "illegal defense", states that a defensive player cannot remain in his own free throw lane for more than 3 seconds unless he is actively guarding an offensive player.
• The "3 position" is the small forward (SF).
• A hat-trick in sports is associated with succeeding at anything three times in three consecutive attempts, as well as when any player in ice hockey or soccer scores three goals in one game (whether or not in succession). In cricket, if a bowler takes 3 wickets in a row it is called a hat trick.
• A threepeat is a term for a team that wins three consecutive championships.
• A triathlon consists of three events: swimming, bicycling, and running.