No, the number four on Roman numeral clocks is not always written as "IIII." It is indeed written as "IV" in most standard and modern Roman numeral systems. The use of "IIII" for the number four on some clocks is an exception based primarily on aesthetic and historical reasons.
Here's a breakdown:
Standard Roman Numerals: In standard Roman numerals used outside of clock faces, the number four is correctly written as "IV." This follows the subtractive principle where one smaller numeral (I) is placed before a larger numeral (V) to indicate subtraction.
Clock Faces: On many antique and some modern clocks, you may see "IIII" used instead of "IV" for the number four. This practice is largely due to:
Modern Exceptions: In contemporary digital or minimalist clocks, you will typically see "IV" used to represent the number four, aligning with the standard Roman numeral system.
In summary, while "IV" is the correct and standard representation of the number four in Roman numerals, you might see "IIII" used on some clock faces due to historical and aesthetic reasons. However, this is not the standard practice in general Roman numeral usage.