A page of the Numeropedia - the Special Encyclopedia of Numbers
... In Arithmetic, 1+1 = 2, in Computer Science, 1+1 = 0, but in Love, 1+1 = 1!
[Astronomy] The number of natural satellites of the Earth: Moon.
[Biology] Every animal has either only 1 tail or none. Every animal has either 1 horn (called unihorn) or 2 horns, or none.
[Biology] Every camel has either 1 or 2 humps. One-humped camel is called dromedary, two-humped camel is called Bactrian camel.
[Biology] A human body has many one organ: head, brain, forehead, nose, mouth, jaw, chin, tongue, neck, throat, heart, liver and stomach…
[Calendar] The first year of the first century or the first year after the year 1 B.C. The date 01/01/01 A.D. is the first day of the first century.
[Calendar] 01/01 or 01-01 is the New Year’s Day.
[Calendar] After the year 1 B.C. is the year 1 A.D. There is no year 0.
[Calendar] Daylight Saving Time in the U.S. starts by moving 1 hour ahead at 2 A.M. on the the second Sunday of March and ends by moving 1 hour back at 2 A.M. on the first Sunday of November. Before the year 2007, it is between the first Sunday of April until the last Sunday of October. In the European Union, Summer Time begins at 1 A.M. on the last Sunday of March and ends at 1 A.M. the last Sunday of October.
[Chemistry] The atomic number of Hydrogen (H).
[Education] A first year college or high school student is a freshman.
[Education] Valedictorian is the top graduate of the entire graduating class of an educational institution, traditionally based on grades and overall GPA. The second-highest graduate is the salutatorian.
[Education] The number of points to which a course’s grade D is transferred, when computing a student’s GPA (general point average) in the popular 4.0-scale GPA system of most schools. A sign +/– may add/subtract .3 or 0.33 to the basic point, depending on schools.
[EECS] The digit represented by the brown color by either first 2 bands or the exponent of 10 represented by that color of the 3rd band (i.e. multiplier is 10) in the electronic resistor/capacitor color code.
[Flag] The number of star on the “Lone Star State” flag of Texas is 1.
[Game] The number of Kings/Queens for each player/side in a chess set.
[Game] The number of Kings/Rooks/Bishops for each player/side in a Shogi (Japanese chess) set.
[Game] The number of Kings (or Generals) for each player/side in a Xingqi (Chinese chess) set.
[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).
[Gov.] Air Force One is the name of the U.S. President airplane. It is flown by the presidential aircrew, maintained by the Presidential Maintenance Branch and assigned to the U.S. Air Force–Air Mobility Command’s 89th Airlift Wing, Andrews Air Force Base, Maryland. (Also, there is only a bed aboard the Air Force One which is, of course, for the U.S. President).
[History] The first U.S. President: George Washington (Federalist, Virginia, 1789-1797).
His Vice President, John Adams (Massachusetts), was the 1st U.S. Vice President.
[History] The First State is the nickname of Delaware, since it was the first state to ratify the U.S. Constitution (written on 19 September 1787, in Philadelphia), on 7 December 1787.
[Language] Roman numeral: I = 1.
[Language] Prefixes: Single, Unique, Singular, Solo, Once, Uni-, Mono-…
[Language] “One” in the only number, written in English, whose letters are in the English alphabetical backward order.
“Forty” is the only number, written in English, whose letters are in the English alphabetical order.
[Library] ISBN-1 and ISBN-0 are the International Standard Book Number codes for books published in English (U.S., United Kingdom, Australia, New Zealand, Canada, South Africa and Zimbabwe).
[Military] A brigadier general is called 1-star general (U.S. military).
[Military] Marine One is the call sign used when the U.S. President is on board of one the HMX-1 Marine helicopters. Currently, it is the Sikorsky VH-3D (Sea King).
[Money] The U.S. $1 bill figures the portrait of the first U.S. President George Washington. On the back is “ONE” between the observe and reverse of the Great Seal of the U.S.
[Movie] Names of TV shows/series or movies: “One Flew Over the Cuckoo’s Nest”, “Capricorn One”, “One Hour Photo”, “The One”, “1 vs. 100”, “One Tree Hill”, “One-Eyed Jack”, “One Man's War”, For One More Day” and “Year One”.
[Phone] International telephone dialing code for U.S. and Canada.
[Phone] The first digit of an NANPA /U.S. 3-digit area code cannot be 0 or 1. The smallest number assigned for an area code, starting with number 2, is 201 for Jersey City and Hackensack, New Jersey. (NANPA: North American Numbering Plan Administration).
[Phone] A 7-digit number after an NANPA/U.S. 3-digit area code cannot start with 0nm, 1nm or 8 other 3-digit numbers: 211, 311, 411, 511, 611, 711, 811 and 911.
[Phone] Before 1995, the middle digit of an NANPA/U.S. 3-digit area code must be either 0 or 1. After this restriction was removed, the middle digit can be any digit from 0 to 8, cannot be 9, which are reserved for expansion codes in the future.
[Theology] Three represents a perfect harmony: the union of unity (one) and diversity (two).
[Library] First 3 digits (000, 001, 002 and 003) in the Dewey Decimal Classification System call numbers for library books in General Knowledge.