A page of the Numeropedia - the Special Encyclopedia of Numbers
[Calendar] Pentecost Sunday (or Whit Sunday) is 49 days after Easter Sunday (or literally from the prefix “pente-“, the 50th day).
[Chemistry] The atomic number of Tin (Sn).
[Chemistry] The number of electrons that can reside in a shell is 2n2, i.e., 2, 8, 18, 32, 50, 72 and 98.
[Chemistry] Solder, the material used for joining iron surfaces, is 50% tin and 50% lead.
[Game] The 50-move rules in chess: if there have been 50 consecutives moves of white and blacks chess pieces without any piece taken or any pawn moved, then a player can claim a draw.
[Game] The highest possible score of a word in the Scrabble game is 164 for the word “Quartzy”: playing across triple-word square with “z” on a double-letter square and a premium of 50 for using all 7 letters on the rack.
[Game] Jigsaw puzzles are typically comprised of 10, 20, 50, 100, 200, 300, 500, 750, 1000, 1500 or 2000 interlocking pieces.
[Game] In the popular TV game show “Deal or No Deal”, a contestant has the choices of one of 26 suitcases of the prizes U.S. $0.01, 1, 5, 10, 25, 50, 75, 100, 200, 300, 400, 500, 750, 1000, 5000, 10,000, 25,000, 50,000, 75,000, 100,000, 200,000, 300,000, 400,000, 500,000, 750,000 and the maximum amount is at least $1,000,000 (in a typical show).
[Game] In the popular TV game show “Who Wants to be a Millionaire?”, a contestant has to answer correctly 15 questions to step up the fixed prizes in U.S.$: 100, 200, 300, 500, 1000, to 2000, 4000, 8000, 16,000, 32,000, to 64,000, 125,000, 250,000, 500,000 and the maximum amount is at least $1,000,000, with 3 lifelines: polling the audience, calling a friend and narrowing to “50:50” answers. The guaranteed middle prizes can be $1000 or $32,000.
[Geology] U.S. cities/towns whose names start with “Fifty”: Fifty Lakes, Minnesota 56448 and Fifty-Six, Arkansas 72533.
[Geology] Nevada’s Highway 50 was named, by “Life” magazine in 1986, the “Loneliest Highway in America”.
[History] The number of the U.S. states (together with the District of Colombia). The 50th state is Hawaii, proclaimed on 21 August 1959. The current 50-star flag (the 20th design since the country was formed) made official debut at Independence Hall, Philadelphia on 4 July 1960.
[History] Hawaii became the 50th state of the U.S. on 21 August 1959.
[History] The U.S. Senate vote result in a tie 50-50 is the only situation that the U.S. Vice-President has a chance to cast his vote to break the tie. If he does not vote, the measure or bill is failed automatically.
[Language] Prefixe: Quinquage-...
[Language] Roman numerals: L = 50 & L-bar or (L) = 50,000.
[Math.] A number is divisible by 25 when it ends with 2 digits 00, 25, 50 or 75.
[Math.] A base system of multigrade equalities: (References [??])
1+4+12+13+20 = 50 = 2+3+10+16+19
12+42+122+132+202 = 730 = 22+32+102+162+192
13+43+123+133+203 = 11,990 = 23+33+103+163+193.
Multigrade equalities still hold by adding any integer n to every base term in both sides. Hence, the base equality always has number 1 appearing in one side.
[Math.] 165,033 = 163+503+333 and its modified number: 1,000,165,033 = 10003+163+503+333. (Generalizable)
[Math.] The smallest number that can be sum of 2 square numbers in 2 ways: 50 = 12+72 = 52+52.
[Measure] The typical number of sheets of paper in a notepad/notebook: 50, 80 or 100.
[Measure] 50-50 (or half-half) is a popular way of fair shares between two parties.
[Measure] 1 liang = 50 g (grams), a traditional Chinese weight unit. (Modern day value).
[Money] The number of cents (pennies) in a half dollar coin. (U.S. coins).
[Money] The number of stars circling around the eagle on the U.S. half dollar coin.
[Money] The U.S. $50 bill figures the portrait of the 18th U.S. President Ulysses Simpson Grant. On the back is the U.S. Capitol.
[Money] By the U.S. law, any picture of U.S. money bill must be either 50% larger or 25% smaller than the real bill, to protect against counterfeit bills.
[Movie] Name of TV show/series or movie: “50 First Dates”.
[Movie] The critical speed in the movie “Speed” is 50 mph.
[Phone] The number of names listed in the first telephone book, (a 1-page list of subscribers), published by the New Haven District Telephone Company, New Haven, Connecticut, in February 21, 1878.
[Science] One of seven magic numbers in nuclear physics: 2, 8, 20, 28, 50, 82 and 126. They are the numbers of nucleons such that they are arranged into complete shells within the atomic nucleus.
[Sport] The length (m, meters) of an Olympic swimming pool.
[Sport] The width (15.24 meters) of a basketball court.
[Sport] The score of when a dart hitting the bull’s-eye (red small center) in a dartboard game. The score for the outer bull’s-eye is 25.
[Sport] The standard ranges of swimming/tracking competitions (meters): 50, 100, 200, 400, 800 and 1500. Also, for tracking: 2000, 3000, 5000 and 10000.
[Sport] The PGA Tour’s Vardon Trophy for lowest scoring average in a year requires playing a minimum of 50 rounds of PGA tournaments.
[Tech.] The HD-DVD will have memory capacity of 15, 30 or 50 GB (gigabytes).
(Toshiba's HD-DVD discs have 30 GB. Sony's Blu-Ray DVD discs have 50 GB.)
[Tech.] The frequency of the A.C. electrical power in many countries, except the U.S. and Canada is 50 Hz (Hertz). (A.C. = alternating current).
[Tech.] The “number system” code of an EAN-13 barcode for the United Kingdom’s products.
[Tech.] The numbers of automobile engine oil SAE viscosity: 20W-20 (-40, -50), 10W-30 (-40) and 5W-20 (-30).
[Trivia] Popular U.S. city street speed limits: 15, 25, 30, 35, 40, 45 or 50 miles/hour.
[Trivia] The 50th wedding anniversary is traditionally/modernly named gold anniversary.
[World] The ISO country code for Bangladesh is 050. (ISO-3166).