3 (number)

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234
−1 0 1 2 3 4 5 6 7 8 9
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
Hexadecimal316
Vigesimal320
Base 36336
Arabic٣,3
Urdu۳
Bengali
Chinese三,弎,叁
Devanāgarī (tin)
Ge'ez
Greekγ (or Γ)
Hebrewג
Japanese
Khmer
Korean셋,삼
Malayalam
Tamil
Telugu
Thai
 
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This article is about the number. For the year, see 3. For other uses, see 3 (disambiguation).
234
−1 0 1 2 3 4 5 6 7 8 9
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
Hexadecimal316
Vigesimal320
Base 36336
Arabic٣,3
Urdu۳
Bengali
Chinese三,弎,叁
Devanāgarī (tin)
Ge'ez
Greekγ (or Γ)
Hebrewג
Japanese
Khmer
Korean셋,삼
Malayalam
Tamil
Telugu
Thai

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

In mathematics[edit]

In numeral systems[edit]

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[edit]

Multiplication12345678910111213141516171819202122232425501001000
3 \times x369121518212427303336394245485154576063666972751503003000
Division123456789101112131415
3 \div x31.510.750.60.50.\overline{428571}0.3750.\overline{3}0.30.\overline{27}0.250.\overline{230769}0.2\overline{142857}0.2
x \div 30.\overline{3}0.\overline{6}11.\overline{3}1.\overline{6}22.\overline{3}2.\overline{6}33.\overline{3}3.\overline{6}44.\overline{3}4.\overline{6}5
Exponentiation12345678910111213
3 ^ x\,3927812437292187656119683590491771475314411594323
x ^ 3\,1827641252163435127291000133117282197

Evolution of the glyph[edit]

Evolution3glyph.png

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 Text figures 036.svg. 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 science[edit]

In religion[edit]

Main article: Triple deity

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

Christianity[edit]

In Buddhism[edit]

In Hinduism[edit]

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

In Norse mythology[edit]

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

Other religions[edit]

In esoteric tradition[edit]

As a lucky or unlucky number[edit]

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 philosophy[edit]

In sports[edit]

See also[edit]

References[edit]

  1. ^ Bryan Bunch, The Kingdom of Infinite Number. New York: W. H. Freeman & Company (2000): 39
  2. ^ Priya Hemenway (2005), Divine Proportion: Phi In Art, Nature, and Science, Sterling Publishing Company Inc., pp. 53–54, ISBN 1-4027-3522-7 
  3. ^ Georges Ifrah, The Universal History of Numbers: From Prehistory to the Invention of the Computer transl. David Bellos et al. London: The Harvill Press (1998): 393, Fig. 24.63
  4. ^ See "bad" in the Oxford Dictionary of Phrase and Fable, 2006, via Encyclopedia.com.

External links[edit]