7 (number)

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7

−1 0 1 2 3 4 5 6 7 8 9

Cardinal7
seven
Ordinal7th
seventh
Numeral systemseptenary
Factorizationprime
Divisors1, 7
Greek numeralZ, ζ
Roman numeralVII
Roman numeral (Unicode)Ⅶ, ⅶ
Amharic
Arabic٧,7
Persian٧ - هفت
Bengali
Chinese numeral七(qi)
Devanāgarī (saat)
Telugu
Tamil
Hebrewז (Zayin)
Khmer
Thai
prefixeshepta-/hept- (from Greek)

septua- (from Latin)

Binary111
Octal7
Duodecimal7
Hexadecimal7
 
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7

−1 0 1 2 3 4 5 6 7 8 9

Cardinal7
seven
Ordinal7th
seventh
Numeral systemseptenary
Factorizationprime
Divisors1, 7
Greek numeralZ, ζ
Roman numeralVII
Roman numeral (Unicode)Ⅶ, ⅶ
Amharic
Arabic٧,7
Persian٧ - هفت
Bengali
Chinese numeral七(qi)
Devanāgarī (saat)
Telugu
Tamil
Hebrewז (Zayin)
Khmer
Thai
prefixeshepta-/hept- (from Greek)

septua- (from Latin)

Binary111
Octal7
Duodecimal7
Hexadecimal7

7 (seven;/ˈsɛvən/) is the natural number following 6 and preceding 8.

Contents

Mathematics

In fact, if one sorts the digits in the number 142857 in ascending order, 124578, it is possible to know from which of the digits the decimal part of the number is going to begin with. The remainder of dividing any number by 7 will give the position in the sequence 124578 that the decimal part of the resulting number will start. For example, 628/7= 89 + 5/7; here 5 is the remainder, and would correspond to number 7 in the ranking of the ascending sequence. So in this case, 628/7 = 89.714285. Another example, 5238/7 = 748 + 2/7, hence the remainder is 2, and this corresponds to number 2 in the sequence. In this case, 5238/7 = 748.285714.

Numeral systems

BaseNumeral system
2binary111
3ternary21
4quaternary13
5quinary12
6senary11
7septenary10
over 7 (octal, decimal, etc.)7

In quaternary, 7 is the smallest prime with a composite sum of digits.

Basic calculations

Multiplication12345678910111213141516171819202122232425501001000
7 × x7142128354249566370778491981051121191261331401471541611681753507007000
Division12345678910
1112131415
7 ÷ x73.52.31.751.41.1610.8750.70.7
0.630.5830.5384610.50.46
x ÷ 70.1428570.2857140.4285710.5714280.7142850.85714211.1428571.2857141.428571
1.5714281.7142851.85714222.142857
Exponentiation12345678910111213
7x74934324011680711764982354357648014035360728247524919773267431384128720196889010407
x71128218716384781252799368235432097152478296910000000194871713583180862748517
Radix151015202530405060708090100
1101201301401502002505001000100001000001000000
x715137217267347427557101711471307143715672027
215723172447260730374047505713137262674110475643557113333117

Evolution of the glyph

SevenGlyph.svg
In the beginning, various Hindus wrote 7 more or less in one stroke as a curve that looks like an uppercase J vertically inverted. The western Ghubar Arabs' main contribution was to make the longer line diagonal rather than straight, though they showed some tendencies to making the character more rectilinear. The eastern Arabs developed the character from a 6-look-alike into an uppercase V-look-alike. Both modern Arab forms influenced the European form, a two-stroke character consisting of a horizontal upper line joined at its right to a line going down to the bottom left corner, a line that is slightly curved in some font variants. As is the case with the European glyph, the Cham and Khmer glyph for 7 also evolved to look like their glyph for 1, though in a different way, so they were also concerned with making their 7 more different. For the Khmer this often involved adding a horizontal line above the glyph.[2] This is analogous to the horizontal stroke through the middle that is sometimes used in handwriting in the Western world but which is almost never used in computer fonts. This horizontal stroke is, however, important to distinguish the glyph for seven from the glyph for one in writings that use a long upstroke in the glyph for 1.

Sevens.svg
Digital77.svg

On the seven-segment displays of pocket calculators and digital watches, 7 is the number with the most common glyph variation (0, 6 and 9 also have variant glyphs). Most calculators use three line segments, but on Sharp, Casio, and a few other brands of calculators, 7 is written with four line segments because, in Japan and Korea, 7 is written as ① in the illustration to the right.

While the shape of the 7 character has an ascender in most modern typefaces, in typefaces with text figures the character usually has a descender, as, for example, in TextFigs078.svg.

Hand Written 7.svg

Most people in Continental Europe[3] and Latin America write 7 with a line in the middle ("7"), sometimes with the top line crooked. The line through the middle is useful to clearly differentiate the character from the number one, as these can appear similar when written in certain styles of handwriting. This glyph is used in official handwriting rules for primary school in Russia, Ukraine and other Slavic countries,[4] as well as in France and Romania.[5]

Automotive and transportation

Classical world

Classical antiquity

Commerce and business

Food and beverages

Media and entertainment

Film

Characters

Titles

Games (other than video games)

Literature

Music

Sports

Baseball
Football and soccer
Frisbee and Ultimate Frisbee
Handball
Motor sports
Rugby
Rugby league
  • The jersey number 7 is worn by the starting scrum-half/halfback in most competitions (but not in the European Super League, which uses static squad numbering).
  • 7, The number of consecutive State of Origin Series wins(2006-2012) by Queensland against New South Wales in Australia. The highest since the inception of the State of Origin Series concept which commenced in 1980.
Rugby union
  • The jersey number 7 is worn by the starting openside flanker. (Some teams use "left" and "right" flankers instead of "openside" and "blindside", with 7 being worn by the starting right flanker.)
  • A converted try is worth 7 points. This number is also significant because the standard bonus points system used in most competitions awards 1 bonus point to a team that loses by 7 points or less.
  • The IRB Sevens World Series, an annual competition for national teams in rugby union sevens (see below)
  • The Rugby World Cup Sevens, the World Cup for the union version of Sevens
Cross-code
  • Rugby sevens, a variant of union and league that contains only seven players per side instead of the standard 15 (union) or 13 (league)
Track and field
Water polo

Television

Networks and stations

Programs

Video games

The seven Chaos Emeralds in Sonic R.
The seven Koopalings as seen in New Super Mario Bros. 2.

Places

Religion

Old Testament

Seven Days of Creation - 1765 book

The number seven (7) in the seven days of Creation is typological and the number seven appears commonly elsewhere in the Bible. These include:

New Testament

Other sevens in Christian knowledge and practice include:

Hinduism

Islam

Judaism

Others

Deity, being, or character
Place
Scripture
Thing, concept, or symbol
Time

Science

Astronomy

Biology

Chemistry

The periodic table has 7 rows of known elements

Physics

Isaac Newton's 7 colors of the rainbow

Psychology

Temporal, seasonal, and holidays

Software and technology

Seven is also

See also

Notes

  1. ^ Bryan Bunch, The Kingdom of Infinite Number. New York: W. H. Freeman & Company (2000): 82
  2. ^ 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): 395, Fig. 24.67
  3. ^ Eeva Törmänen (8.9.2011). "Aamulehti: Opetushallitus harkitsee numero 7 viivan palauttamista" (in Finnish). Tekniikka & Talous. http://www.tekniikkatalous.fi/viihde/aamulehti+opetushallitus+harkitsee+numero+7+viivan+palauttamista/a682831. 
  4. ^ "Education writing numerals in grade 1."(Russian)
  5. ^ "Example of teaching materials for pre-schoolers"(French)
  6. ^ 21Then Peter came to Jesus and asked, 'Lord, how many times shall I forgive my brother when he sins against me? Up to seven times?' 22Jesus answered, 'I tell you, not seven times, but seventy times seven.'
  7. ^ "Sermon Illustrations". Bible.org. http://www.bible.org/illus.php?topic_id=1510. Retrieved 2012-09-07. 
  8. ^ "''Encyclopædia Britannica'' "Number Symbolism"". Britannica.com. http://www.britannica.com/EBchecked/topic/1086220/number-symbolism/248164/7. Retrieved 2012-09-07. 
  9. ^ "SI brochure, The seven SI base units". http://www.bipm.org/en/si/si_brochure/chapter2/2-1/#2-1-2. Retrieved 2009-09-11. 
  10. ^ "SI brochure, SI derived units". http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html. Retrieved 2009-09-11. 

References

External links