9 in Roman Numerals
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9 in Roman numerals is IX. 9 is 10 minus 1, so I goes before X: IX. VIIII is not standard: it puts four Is in a row, one more than the rules allow, so the ones are written IX. In lowercase it is ix, and the number is nine.
How IX is built
ones9 = 10 − 1 → IX
9 is 10 minus 1, so I goes before X: IX.
What sets IX apart
- IX is a subtractive pair
- I written before X means 10 minus 1. Written after it, as XI, the same I would be added and give 11.
- No letter repeats
- Each of the two letters in IX appears once.
- Two letters shorter
- From 8 to 9 only the ones change, VIII becoming IX, and the numeral loses two letters.
- Doubled: 18
- Double it and you reach 18 (XVIII): the subtraction in IX disappears, and XVIII is written by adding only.
Where you see IX
Sport
Super Bowl IX was played on January 12, 1975, in New Orleans, where the Pittsburgh Steelers beat the Minnesota Vikings 16–6. Wikipedia The Games of the IX Olympiad were the 1928 Summer Olympics in Amsterdam. Wikipedia
Kings, queens and popes
Louis IX of France, reigning 1226–1270, is the only French king canonized as a saint. Wikipedia
Films, games, books and software
Star Wars: The Rise of Skywalker (2019) is Episode IX of the saga. Wikipedia
Events and history
WrestleMania IX, held at Caesars Palace near Las Vegas on April 4, 1993, was the first WrestleMania held outdoors. Wikipedia
On clock faces and in Unicode
Clock faces that use IIII for four still write nine as IX, not VIIII. Wikipedia
Mistakes with 9
VIIII is an old additive form; the standard form of 9 is IX. Wikipedia
Numbers near 9
