20 (number)

20 (twenty; Roman numeral XX) is the natural number following 19 and preceding 21. A group of twenty units may also be referred to as a score.[1][2]

← 19 20 21 →
Cardinaltwenty
Ordinal20th
(twentieth)
Numeral systemvigesimal
Factorization22 × 5
Divisors1, 2, 4, 5, 10, 20
Greek numeralΚ´
Roman numeralXX
Binary101002
Ternary2023
Octal248
Duodecimal1812
Hexadecimal1416

In mathematicsEdit

 
An icosahedron has 20 faces

In scienceEdit

BiologyEdit

  • The number of proteinogenic amino acids that are encoded by the standard genetic code.
  • In some countries, the number 20 is used as an index in measuring visual acuity. 20/20 indicates normal vision at 20 feet, although it is commonly used to mean "perfect vision". (Note that this applies only to countries using the Imperial system. The metric equivalent is 6/6.) When someone is able to see only after an event how things turned out, that person is often said to have had "20/20 hindsight".[12]

As an indefinite numberEdit

  • A 'score' is a group of 20 (often used in combination with a cardinal number, i.e. fourscore to mean 80),[13] but also often used as an indefinite number[14] (e.g. the newspaper headline "Scores of Typhoon Survivors Flown to Manila").[15]

In sportsEdit

 
A standard dartboard is laid out as 20 sectors

Age 20Edit

MusicEdit

Albums
20 Related Twenty Related
Harry Connick, Jr.[24] 20+ Baron Rojo[25] Bob Baldwin[26] Twenty+ All-4-One[27]
Orbital[28] 20% Maria Bamford[29] Boyz II Men[30] 20 [Twenty] FT Island[31]
TLC[32] Chicane[33]
Jars of Clay[34] Robert Cray[35]
Africa Unite[36] Jebediah[37]
Kate Rusby[38] Lynyrd Skynyrd[39]
Hyukoh[40] Taking Back Sunday[41]
Pastora Soler[42]
The Gift[43]
Sofa Surfers[44]
Capo Plaza[45]
John Dahlbäck[46]
Songs
20 Related Twenty
Ebbo Kraan[47] #20 - Fat Tuesday[48] The Rippingtons[49]
Seventeen[50] #20 - Aphex Twin[51]
Janet Jackson[52] #20 - Tony Wilson Sextet[53]
Gorky's Zygotic Mynci[54] #20 - David Paul Mesler[55]
Covenant[56] $20 - Low (band)[57]
Car 44[58] $20 - Qwiksand[59]
Karma to Burn[60] $20 - Norman Palm[61]
Ike Yard[62] 20% - Furyus[63]
Noah Stone[64] 20% - Banfi[65]
Alec Empire[66] -20 - Brendon Moeller[67]
Beans[68] -20 - Mr. 76ix[69]
Damián Schwartz[70] 20 (intro) - Janet Jackson[71]
Anarchestra[72] 20 (Palbarrio) - El Barrio[73]

In other fieldsEdit

See alsoEdit

ReferencesEdit

  1. ^ John H. Conway and Richard K. Guy, The Book of Numbers. New York: Copernicus (1996): 11. ""Score" is related to "share" and comes from the Old Norse "skor" meaning a "notch" or "tally" on a stick used for counting. ... Often people counted in 20s; every 20th notch was larger, and so "score" also came to mean 20."
  2. ^ "score | Origin and meaning of score by Online Etymology Dictionary". www.etymonline.com. Retrieved 2020-08-16.
  3. ^ "Sloane's A002378: Pronic numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2020-11-30.
  4. ^ "Sloane's A000292 : Tetrahedral numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-31.
  5. ^ Weisstein, Eric W. "Vigesimal". mathworld.wolfram.com. Retrieved 2020-08-16.
  6. ^ "Sloane's A071395 : Primitive abundant numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-31.
  7. ^ Weisstein, Eric W. "Icosahedron". mathworld.wolfram.com. Retrieved 2020-08-16.
  8. ^ Weisstein, Eric W. "Dodecahedron". mathworld.wolfram.com. Retrieved 2020-08-16.
  9. ^ Dunlap, R. A. (1997). The Golden Ratio and Fibonacci Numbers. World Scientific. pp. 72–73. ISBN 978-981-238-630-4.
  10. ^ "God's Number is 20". Cube20.org
  11. ^ Jonathan Fildes (August 11, 2010). "Rubik's Cube quest for speedy solution comes to an end". BBC News.
  12. ^ "Definition of 20/20". www.merriam-webster.com. Retrieved 2020-08-16.
  13. ^ "Definition of SCORE". www.merriam-webster.com. Retrieved 2020-08-16.
  14. ^ "Biblical Criticism", The Classical Journal 36:71:83ff (March 1827) full text
  15. ^ "CBS News", Scores of Typhoon Survivors Flown to Manila (November 2013)
  16. ^ Cleaver, Dylan (2010-11-03). Brendon McCullum: Inside Twenty20. Hachette New Zealand. ISBN 978-1-86971-238-9.
  17. ^ Ziemba, William T. (2017-08-23). The Adventures Of A Modern Renaissance Academic In Investing And Gambling. World Scientific. p. 352. ISBN 978-981-314-853-6. It has always been for a long time a maximum of 20 horses ...
  18. ^ Jordan, Bill. Opening Moves Made Easy: A new way to learn how to play Chess openings. Bill Jordan. there are 20 legal moves for White and 20 legal replies for Black
  19. ^ Draper, Nick (2014-12-05). Exercise Physiology: For Health and Sports Performance. Routledge. p. 404. ISBN 978-1-317-90260-7. played over four 20 min quarters
  20. ^ Harari, P. J.; Ominsky, Dave (2002). Basketball Made Simple: A Spectator's Guide. First Base Sports, Inc. p. 58. ISBN 978-1-884309-13-7. Duration two 20-min. halves
  21. ^ "International Ice Hockey Federation - Olympic Sport". International Olympic Committee. 9 November 2020. Retrieved 22 January 2021.
  22. ^ "Adulthood | Introduction to Psychology". lumenlearning.com.
  23. ^ "Japan's Age of Majority Changed to 18 - Living the Japon.com". www.japan-experience.com. Retrieved 19 March 2018.
  24. ^ 20 - Harry Connick, Jr. | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  25. ^ 20+ - Baron Rojo | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  26. ^ Twenty - Bob Baldwin | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  27. ^ Twenty + - All-4-One | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  28. ^ 20 - Orbital | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  29. ^ 20 - Harry Connick, Jr. | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  30. ^ Twenty - Boyz II Men | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  31. ^ 20 (Twenty) - FT Island | User Reviews | AllMusic, retrieved 2020-08-17
  32. ^ 20 - TLC | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  33. ^ Twenty - Chicane | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  34. ^ 20 - Jars of Clay | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  35. ^ Twenty - Robert Cray | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  36. ^ 20 - Africa Unite | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  37. ^ Twenty - Jebediah | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  38. ^ 20 - Kate Rusby | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  39. ^ Twenty - Lynyrd Skynyrd | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  40. ^ 20 - Hyukoh | User Reviews | AllMusic, retrieved 2020-08-16
  41. ^ Twenty - Taking Back Sunday | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  42. ^ 20 - Pastora Soler | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  43. ^ 20 - The Gift | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  44. ^ 20 - Sofa Surfers | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  45. ^ 20 - Capo Plaza | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  46. ^ 20 - John Dahlbäck | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  47. ^ 20 - Ebbo Kraan | Song Info | AllMusic, retrieved 2020-08-17
  48. ^ #20 - Fat Tuesday | Song Info | AllMusic, retrieved 2020-08-17
  49. ^ Twenty - The Rippingtons | Song Info | AllMusic, retrieved 2020-08-17
  50. ^ 20 - Seventeen | Song Info | AllMusic, retrieved 2020-08-17
  51. ^ #20 - Aphex Twin | Song Info | AllMusic, retrieved 2020-08-17
  52. ^ 20 - Janet Jackson | Song Info | AllMusic, retrieved 2020-08-17
  53. ^ #20 - Tony Wilson Sextet | Song Info | AllMusic, retrieved 2020-08-17
  54. ^ 20 - Gorky's Zygotic Mynci | Song Info | AllMusic, retrieved 2020-08-17
  55. ^ # 20 - David Paul Mesler | Song Info | AllMusic, retrieved 2020-08-17
  56. ^ 20 - Covenant | Song Info | AllMusic, retrieved 2020-08-17
  57. ^ $20 - Low | Song Info | AllMusic, retrieved 2020-08-17
  58. ^ 20 - Car 44 | Song Info | AllMusic, retrieved 2020-08-17
  59. ^ $20 - Qwiksand | Song Info | AllMusic, retrieved 2020-08-17
  60. ^ 20 - Karma to Burn | Song Info | AllMusic, retrieved 2020-08-17
  61. ^ $20 - Norman Palm | Song Info | AllMusic, retrieved 2020-08-17
  62. ^ 20 - Ike Yard | Song Info | AllMusic, retrieved 2020-08-17
  63. ^ 20% - Furyus | Song Info | AllMusic, retrieved 2020-08-17
  64. ^ 20 - Noah Stone | Song Info | AllMusic, retrieved 2020-08-17
  65. ^ 20% - Banfi | Song Info | AllMusic, retrieved 2020-08-17
  66. ^ 20 - Alec Empire | Song Info | AllMusic, retrieved 2020-08-17
  67. ^ -20 - Brendon Moeller | Song Info | AllMusic, retrieved 2020-08-17
  68. ^ 20 - Beans | Song Info | AllMusic, retrieved 2020-08-17
  69. ^ -20 - Mr. 76ix | Song Info | AllMusic, retrieved 2020-08-17
  70. ^ 20 - Damián Schwartz | Song Info | AllMusic, retrieved 2020-08-17
  71. ^ 20 (Intro) - Janet Jackson | Song Info | AllMusic, retrieved 2020-08-17
  72. ^ 20 - Anarchestra | Song Info | AllMusic, retrieved 2020-08-17
  73. ^ 20 (Palbarrio) - El Barrio | Song Info | AllMusic, retrieved 2020-08-17
  74. ^ "international phone country calling codes". www.globaltel.com. Retrieved 2020-08-16.
  75. ^ "CB Slang: Ten Codes". www.cbslang.com. Retrieved 2020-08-16.
  76. ^ "Welcome to the Online Browsing Platform (OBP)". www.iso.org. Retrieved 2020-08-16.
  77. ^ "Topical Bible: Kaph". biblehub.com. Retrieved 2020-08-17.
  78. ^ Toone, Matthew (2009). Great Games!: 175 Games and Activities for Families, Groups and Children. Great Games Book. p. 145. ISBN 978-0-9798345-5-4. Much like the classic game of 20 Questions,...

External linkEdit