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".[13]

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),[14] but also often used as an indefinite number[15] (e.g. the newspaper headline "Scores of Typhoon Survivors Flown to Manila").[16]

In sportsEdit

 
A standard dartboard is laid out as 20 sectors.

Age 20Edit

MusicEdit

Albums
20 Related Twenty Related
Harry Connick, Jr.[25] 20+ Baron Rojo[26] Bob Baldwin[27] Twenty+ All-4-One[28]
Orbital[29] 20% Maria Bamford[30] Boyz II Men[31] 20 [Twenty] FT Island[32]
TLC[33] Chicane[34]
Jars of Clay[35] Robert Cray[36]
Africa Unite[37] Jebediah[38]
Kate Rusby[39] Lynyrd Skynyrd[40]
Hyukoh[41] Taking Back Sunday[42]
Pastora Soler[43]
The Gift[44]
Sofa Surfers[45]
Capo Plaza[46]
John Dahlbäck[47]
Songs
20 Related Twenty
Ebbo Kraan[48] #20 - Fat Tuesday[49] The Rippingtons[50]
Seventeen[51] #20 - Aphex Twin[52]
Janet Jackson[53] #20 - Tony Wilson Sextet[54]
Gorky's Zygotic Mynci[55] #20 - David Paul Mesler[56]
Covenant[57] $20 - Low (band)[58]
Car 44[59] $20 - Qwiksand[60]
Karma to Burn[61] $20 - Norman Palm[62]
Ike Yard[63] 20% - Furyus[64]
Noah Stone[65] 20% - Banfi[66]
Alec Empire[67] -20 - Brendon Moeller[68]
Beans[69] -20 - Mr. 76ix[70]
Damián Schwartz[71] 20 (intro) - Janet Jackson[72]
Anarchestra[73] 20 (Palbarrio) - El Barrio[74]

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. ^ Sloane, N. J. A. (ed.). "Sequence A006958 (Number of parallelogram polyominoes with n cells (also called staircase polyominoes, although that term is overused))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  13. ^ "Definition of 20/20". www.merriam-webster.com. Retrieved 2020-08-16.
  14. ^ "Definition of SCORE". www.merriam-webster.com. Retrieved 2020-08-16.
  15. ^ "Biblical Criticism", The Classical Journal 36:71:83ff (March 1827) full text
  16. ^ "CBS News", Scores of Typhoon Survivors Flown to Manila (November 2013)
  17. ^ Cleaver, Dylan (2010-11-03). Brendon McCullum: Inside Twenty20. Hachette New Zealand. ISBN 978-1-86971-238-9.
  18. ^ 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 ...
  19. ^ 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
  20. ^ 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
  21. ^ 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
  22. ^ "International Ice Hockey Federation - Olympic Sport". International Olympic Committee. 9 November 2020. Retrieved 22 January 2021.
  23. ^ "Adulthood | Introduction to Psychology". lumenlearning.com.
  24. ^ "Japan's Age of Majority Changed to 18 - Living the Japon.com". www.japan-experience.com. Retrieved 19 March 2018.
  25. ^ 20 - Harry Connick, Jr. | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  26. ^ 20+ - Baron Rojo | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  27. ^ Twenty - Bob Baldwin | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  28. ^ Twenty + - All-4-One | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  29. ^ 20 - Orbital | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  30. ^ 20 - Harry Connick, Jr. | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  31. ^ Twenty - Boyz II Men | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  32. ^ 20 (Twenty) - FT Island | User Reviews | AllMusic, retrieved 2020-08-17
  33. ^ 20 - TLC | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  34. ^ Twenty - Chicane | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  35. ^ 20 - Jars of Clay | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  36. ^ Twenty - Robert Cray | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  37. ^ 20 - Africa Unite | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  38. ^ Twenty - Jebediah | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  39. ^ 20 - Kate Rusby | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  40. ^ Twenty - Lynyrd Skynyrd | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  41. ^ 20 - Hyukoh | User Reviews | AllMusic, retrieved 2020-08-16
  42. ^ Twenty - Taking Back Sunday | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  43. ^ 20 - Pastora Soler | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  44. ^ 20 - The Gift | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-16
  45. ^ 20 - Sofa Surfers | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  46. ^ 20 - Capo Plaza | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  47. ^ 20 - John Dahlbäck | Songs, Reviews, Credits | AllMusic, retrieved 2020-08-17
  48. ^ 20 - Ebbo Kraan | Song Info | AllMusic, retrieved 2020-08-17
  49. ^ #20 - Fat Tuesday | Song Info | AllMusic, retrieved 2020-08-17
  50. ^ Twenty - The Rippingtons | Song Info | AllMusic, retrieved 2020-08-17
  51. ^ 20 - Seventeen | Song Info | AllMusic, retrieved 2020-08-17
  52. ^ #20 - Aphex Twin | Song Info | AllMusic, retrieved 2020-08-17
  53. ^ 20 - Janet Jackson | Song Info | AllMusic, retrieved 2020-08-17
  54. ^ #20 - Tony Wilson Sextet | Song Info | AllMusic, retrieved 2020-08-17
  55. ^ 20 - Gorky's Zygotic Mynci | Song Info | AllMusic, retrieved 2020-08-17
  56. ^ # 20 - David Paul Mesler | Song Info | AllMusic, retrieved 2020-08-17
  57. ^ 20 - Covenant | Song Info | AllMusic, retrieved 2020-08-17
  58. ^ $20 - Low | Song Info | AllMusic, retrieved 2020-08-17
  59. ^ 20 - Car 44 | Song Info | AllMusic, retrieved 2020-08-17
  60. ^ $20 - Qwiksand | Song Info | AllMusic, retrieved 2020-08-17
  61. ^ 20 - Karma to Burn | Song Info | AllMusic, retrieved 2020-08-17
  62. ^ $20 - Norman Palm | Song Info | AllMusic, retrieved 2020-08-17
  63. ^ 20 - Ike Yard | Song Info | AllMusic, retrieved 2020-08-17
  64. ^ 20% - Furyus | Song Info | AllMusic, retrieved 2020-08-17
  65. ^ 20 - Noah Stone | Song Info | AllMusic, retrieved 2020-08-17
  66. ^ 20% - Banfi | Song Info | AllMusic, retrieved 2020-08-17
  67. ^ 20 - Alec Empire | Song Info | AllMusic, retrieved 2020-08-17
  68. ^ -20 - Brendon Moeller | Song Info | AllMusic, retrieved 2020-08-17
  69. ^ 20 - Beans | Song Info | AllMusic, retrieved 2020-08-17
  70. ^ -20 - Mr. 76ix | Song Info | AllMusic, retrieved 2020-08-17
  71. ^ 20 - Damián Schwartz | Song Info | AllMusic, retrieved 2020-08-17
  72. ^ 20 (Intro) - Janet Jackson | Song Info | AllMusic, retrieved 2020-08-17
  73. ^ 20 - Anarchestra | Song Info | AllMusic, retrieved 2020-08-17
  74. ^ 20 (Palbarrio) - El Barrio | Song Info | AllMusic, retrieved 2020-08-17
  75. ^ "international phone country calling codes". www.globaltel.com. Retrieved 2020-08-16.
  76. ^ "CB Slang: Ten Codes". www.cbslang.com. Retrieved 2020-08-16.
  77. ^ "Welcome to the Online Browsing Platform (OBP)". www.iso.org. Retrieved 2020-08-16.
  78. ^ "Topical Bible: Kaph". biblehub.com. Retrieved 2020-08-17.
  79. ^ 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 linksEdit