Title: Roman numerals
Content:  While subtractive notation for 4, 40 and 400 (, and ) has been the usual form since Roman times, additive notation to represent these numbers (,  and ) continued to be used, including in compound numbers like, , and. The additive forms for 9, 90, and 900 (,, and ) have also been used, although less often. The two conventions could be mixed in the same document or inscription, even in the same numeral. For example, on the numbered gates to the Colosseum, is systematically used instead of, but subtractive notation is used for ; so that gate 44 is labelled. Modern clock faces that use Roman numerals still very often use for four o'clock but  for nine o'clock, a practice that goes back to very early clocks such as the Wells Cathedral clock of the late 
Title: Roman numerals
Content:  faces. For instance, on the clock of Big Ben (designed in 1852), the hours from 1 to 12 are written as: The notations and  can be read as "one less than five" (4) and "one less than ten" (9), although there is a tradition favouring representation of "4" as "" on Roman numeral clocks. Other common uses include year numbers on monuments and buildings and copyright dates on the title screens of movies and television programs. , signifying "a thousand, and a hundred less than another thousand", means 1900, so 1912 is written. For the years of this century, indicates 2000. The current year is (2022).
Title: Clock face
Content:  has hours numbered 1–24 around the outside, and the hour hand makes only one revolution per day. Some special-purpose clocks, such as timers and sporting event clocks, are designed for measuring periods less than one hour. Clocks can indicate the hour with Roman numerals or Hindu–Arabic numerals, or with non-numeric indicator marks. The two numbering systems have also been used in combination, with the prior indicating the hour and the latter the minute. Longcase clocks (grandfather clocks) typically use Roman numerals for the hours. Clocks using only Arabic numerals first began to appear in the mid-18th century. The clock face is so familiar that the numbers are often omitted and replaced with unlabeled graduations (marks), particularly in the case of watches. Occasionally, markings of any sort are dispensed with, and the time is read by the angles of the hands.
Title: 24-hour analog dial
Content:  hours, and another set on the right side of the dial to represent the afternoon and evening hours. In Italy, the numbers from 1 to 24 (I to XXIV in Roman numerals) were used, leading to the widespread use of the 24-hour system in that country. On Italian clocks, though, the I was often shown at the right side of the dial, rather than the top. This probably reflects the influence of the Italian timekeeping system, which started counting the hours of the day at sunset or twilight. In northern Europe, the double XII system was gradually superseded during the 14th and 15th centuries by 
Title: Grand Central Terminal art
Content:  There is a 13 ft clock on top of the south facade. The clock, like several others in the terminal, was designed by the Self Winding Clock Company. The clock face uses Roman numerals; its numeral "IIII" is traditional for clock faces displaying the number four, instead of the more common "IV". The numeral "VI", on the bottom of the clock, hides a flap that is used for maintenance.
Title: Legacy of the Roman Empire
Content:   Roman numerals continued as the primary way of writing numbers in Europe until the 14th century, when they were largely replaced in common usage by Hindu–Arabic numerals. The Roman numeral system continues to be widely used, however, in certain formal and minor contexts, such as on clock faces, coins, in the year of construction on cornerstone inscriptions, and in generational suffixes (such as Louis XIV or William Howard Taft IV). Romance languages (and also other languages such as Russian, Polish and Basque) write centuries in Roman numbers; in Spanish, for example, "21st century" is written siglo XXI. The Romans solidified the modern concept of the hour as one-24th part of a day and night. The English measurement system also retains features of the Ancient Roman foot (11.65 modern inches), which was used in England prior to the Anglo-Saxon settlement of Britain. The inch itself derives from the Roman uncia, meaning one-twelfth part.
Title: 4
Content:  canonical four-character idiom. ; In the NATO phonetic alphabet, the digit 4 is called "fower". ; In Astrology, Cancer is the 4th astrological sign of the Zodiac. In Tarot, The Emperor is the fourth trump or Major Arcana card. ; In Tetris, a game named for the Greek word for 4, every shape in the game is formed of 4 blocks each. ; 4 represents the number of Justices on the Supreme Court of the United States necessary to grant a writ of certiorari (i.e., agree to hear a case; it is one less than the number necessary to render a majority decision). ; Number Four is a character in the book series Lorien Legacies. ; In the performing arts, the fourth wall is an imaginary barrier which separates the audience from the performers, and is "broken" when performers communicate directly to the audience.   
Title: World Clock (Alexanderplatz)
Content:  observer – it is only readily apparent in timelapse recordings. Numbers – in a line from one through twenty-four – revolve around the outside of the clock throughout the day. To read the clock, a user finds the side of the icositetragon which corresponds to the city or time zone they are interested in and notes the number under it. The number corresponds to the current hour in that city. If the number is not directly under the side, but is instead off-set by some fraction, that can be used as a way to estimate the number of minutes past the hour it is in that city. This is made easier because each number is in a different-colored rectangle, the length of which corresponds to one side of 
Title: Astronomical clock
Content:  is for the astronomical clocks designed for use in the northern hemisphere.) This interpretation is most accurate at the equinoxes, of course. If XII is not at the top of the dial, or if the numbers are Arabic rather than Roman, then the time may be shown in Italian hours (also called Bohemian, or Old Czech, hours). In this system, 1 o'clock occurs at sunset, and counting continues through the night and into the next afternoon, reaching 24 an hour before sunset. In the photograph of the Prague clock shown at the top of the article, the time indicated by the Sun hand is about 9am (IX in Roman numerals), or about the 13th hour (Italian time in Arabic numerals).
Title: Numerals in Unicode
Content:  Roman numerals originated in ancient Rome, adapted from Etruscan numerals. The system used in classical antiquity was slightly modified in the Middle Ages to produce the system we use today. It is based on certain letters which are given values as numerals. Roman numerals are commonly used today in numbered lists (in outline format), clockfaces, pages preceding the main body of a book, chord triads in music analysis (Roman numeral analysis), the numbering of movie and video game sequels, book publication dates, successive political leaders or children with identical names, and the numbering of some sport events, such as the Olympic Games or the Super Bowl. Unicode has a 

Question: number 4 in roman numerals on clock faces?
Answer: IV.