A page of the Numeropedia - the Special Encyclopedia of Numbers
[Astronomy] On August 24, 2006, the International Astronomical Union voted to demote Pluto (discovered in 1930 and has considered the 9th planet in the Solar System) to “dwarf planet”, leaving the Solar System of only 8 planets: (listed from the nearest to the Sun): Mercury (8th largest by diameter), Venus (6th), Earth (5th), Mars (7th), Jupiter (1st), Saturn (2nd), Uranus (3rd) and Neptune (4th). Pluto is now assigned the asteroid number 134340 by the Minor Planet Center.
[Calendar] September was meant the 7th month in Latin. November was meant the 9th month in Latin.
[Calendar] September’s birthstone is sapphire or lapis lazuli (for truth).
September’s flower is aster or morning glory. September’s full moon is named “Harvest Moon”.
September’s full moon is named “Harvest Moon”.
[Chemistry] The atomic number of Fluorine (F).
[Education] The number of months in an academic year.
[EECS] The digit represented by the white color by either first 2 bands or the exponent of 10 represented by that color of the 3rd band (i.e. multiplier is 109) in the electronic resistor/capacitor color code.
[Flag] The number of gold stars interspersed with laurel leaves on the wreath encircling the seal on the New Hampshire state flag, representing the 9th state of the Union.
[Flag] The number of yellow stars (representing the map of the country) on the national flag of Tuvalu, representing its 9 islands.
[Flag] The number of equal horizontal stripes of white (from top) alternating with blue on the national flag of Uruguay.
[Game] The size of a Shogi (Japanese chess) board is: 9´9. The board is un-checkered.
[Game] The number of Pawns for each player/side in a Shogi (Japanese chess) set.
[Game] The number of squares in a tic-tac-toe game board (3´3).
[Game] The number of vertical lines of a Xiangqi (Chinese chess)board. It has 10 horizontal lines.
[Game] The number of smaller cubes (or squares) on each face of a Rubik’s cube.
[Game] Sudoku is played on a 9×9 grid, which is divided into nine 3´3 boxes. The object is to fill it so that every row, column and 3´3 box contains each of 9 digits 1-9 once.
[Geology] The number of mouths/tributaries of the Mekong river (the river of Nine Dragons, in Vietnam) in southeastern Asia at its estuary in southern Vietnam, before it reaches the South China Sea: Tiểu, Ðại, Ba Lai, Hàm-Luông, Cổ-Chiên and Cung-Hầu (belonging to Tiền-Giang branch) and Ðịnh-An, Ba-Thác (Basaac) and Tranh-Ðề (Hậu-Giang branch).
[Geology] The number of bordering countries of German: Austria, Belgium, Czech Republic, Denmark, France, Luxembourg, Netherlands, Poland and Switzerland.
[Geology] U.S. cities/towns whose names start with “Nine”: Nine Mile, Indiana – Nine Mile, Florida – Nine Mile, Michigan and Nine-mile, Montana.
[Gov.] A U.S. senator must be a U.S. citizen over 30 years old and residing in the U.S. over 9 years
[Gov.] A U.S. Social Security number has 9 digits, in the format: AAA-GG-SSSS, AAA is area number (indicating location issued, less than 750), GG is group number (indicating time issued, in the order of odd numbers under 10 (01, 03,…, 09), even numbers above 10 (10, 12,…, 98), even numbers under 10 (02, 04,…, 08) and odd number above 10 (11, 13,…, 99)) and SSSS is serial number (0001 to 9999, assigned to local offices until 1972). All 00, 000 and 0000 are invalid area number, group number and serial number, respectively.
[History] The number of Judges of the U.S. Supreme Court.
[History] The number of days that Lady Jane Grey was Queen of England in 1553.
[History] New Hampshire was the 9th state to ratify the U.S. Constitution to join the Union, on 21 June 1788.
[History] The 9th U.S. President: William Henry Harrison (Whig, Virginia, March-April 1841).
[History] U.S. National Hispanic Heritage month is from September 15 to October 15.
[Language] Prefixes: Nonus-, Novem-, Ennea, Nona-…
[Language] Cloud 9: very happy, very high. In meteorology, cloud nine is cumulo-nimbus cloud at the height of 10 km.
[Language] The number of letters in the longest English word with only one syllable: strengths (even only one vowel) and screeched. In fact, strength is the only eight-letter word with only one vowel.
[Measure] The number of square feet in a square yard.
U.S. customary units for area measures: 1 acre = 160 square rods = 4,840 square yards = 43,560 square feet = 6,272,640 square inches = 4046.8564224 m2 & 1 square mile (1 section) = 640 acres = 2,589,988.11 m2 = 2.59 km2 = 259 hectares & 1 hectare = 2.471 acres = 10,000 m2 & 1 township = 36 square miles.
[Measure] The number of inches in a span, the distance between the end of the thumb to the end of the little finger when both are outstretched.
[Measure] Mohs hardness scale for estimating the hardness of minerals or solid substances: diamond 10, corundum 9, topaz 8, quartz 7, orthoclase 6, apatite 5, fluorite 4, calcite 3, gypsum 2 and talc 1.
[Measure] The 9 o’clock direction is left-hand side.
[Money] A U.S. Social Security number has 9 digits, in the format: AAA-GG-SSSS, AAA is area number (indicating location issued, less than 750), GG is group number (indicating time issued, in the order of odd numbers under 10, even numbers above 10, even numbers under 10 and odd number above 10) and SSSS is serial number (assigned to local offices until 1972).
[Money] The number of digits of a bank account routing number.
[Money] The number of stars forming an arch on top of the eagle on the U.S. half dollar coin. There are also 50 stars circling around the eagle. There are also 9 stars forming an arch on top of the eagle.
[Movie] Names of TV shows/series or movies: “The Nine”, “Love Potion #9”, “9 Songs”, “Nine Lives”, “The Nines”, “The Whole Nine Yards” (and its sequel “The Whole Ten Yards”), “The Ninth Gate” and “9”.
[Phone] The digit that can be dialed mnemonically by either letter W, X or Y (or maybe Z) on the telephone keypad.
[Phone] The number to key in text messaging on telephone keypad for letter W.
[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. (NANPA: North American Numbering Plan Administration).
[Trivia] The 9th wedding anniversary is traditionally named pottery (or pillow) anniversary. Modernly, it may be replaced by leather (or lapis).
[Trivia] K-9: a “canine” unit of police department.
[Trivia] “Nine to Five” is a standard working schedule for a day.
[Trivia] TV Screen Aspect ratios: Regular [4:3] (for “Pan & Scan” or “Letterbox”) and “Widescreen” [16:9].
[Trivia] Morse code for number 9 is 4 dashes and 1 dot [ _ _ _ _ . ]
Flag semaphore signal for number 9 is that of letter I.
[Zip] U.S. Postal Service Zip+4 Code, (or 9-digit Zip+4 codes) instituted in 1983, is an expanded 5-digit Zip Code (instituted in 1963) plus a 4-digit add-on code to identify a geographic segment within the 5-digit delivery area for more efficient mail sorting and delivery.
[Tech.] The “number system” code of an EAN-13 barcode for the U.S. and Canada’s products: 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12 and 13.
[Measure] 1 peck = 9.09 l (liters). British imperial units for dry and liquid measures: 1 bushel = 4 pecks = 8 gallons = 32 quarts = 64 pints = 256 gills = 1280 fluidounces = 36.368736 liters.
[EECS] 9.1(W, KW or MW) is one of standard numerical values for resistors (of tolerance class 5%).
[Movie] Names of TV shows/series or movies: “The First 9½ Weeks”, “9½ Weeks” and “Another 9½ Weeks”.
8 & 9
[History] The 8th U.S. President: Martin Van Buren (Democrat, New York, 1837-1841).
His Vice President, Richard Mentor Johnson (Kentucky), was the 9th U.S. Vice President.
9 & 10
[Movie] The 9th U.S. President: William Henry Harrison (Whig, Virginia, March-April 1841).
His Vice President , John Tyler (Democrat, Virginia, 1841) was the 10th U.S. Vice President).