why number four in roman clocks is usually be written as IIII instead of IV

The reason why the number four in Roman numerals is often written as "IIII" instead of "IV" on some clocks is largely due to aesthetic and functional reasons rather than historical or mathematical accuracy. 1. Symmetry: Clock faces are circular, and using "IIII" instead of "IV" creates symmetry with the other numbers. This makes the clock look more balanced and evenly spaced, which can be particularly important on analog clock dials. 2. Readability: The repetition of the "I" (one) character makes the number easier to read quickly, especially at a glance. "IIII" is visually distinct from the adjacent numbers, reducing confusion and making it stand out like the other single, double, and triple representations. 3. Consistency with Ancient Practice: In ancient Roman times, "IIII" was sometimes indeed used instead of "IV" to represent the number four. This practice may have persisted and influenced clock design. 4. Counterbalance Limitations: Mechanical clocks had to keep moving parts balanced for precise timekeeping. Early clock designers might have chosen "IIII" to balance the rotation and movement of the clock hands symmetrically. 5. Stigma of the Number IV: In some contexts, the number "IV" is considered less desirable due to its similarity to words associated with negativity or death (like "ill" or "end" in English). Using "IIII" could circumvent this superstition. However, it's important to note that "IV" is widely recognized and accepted as the standard representation of the number four in Roman numerals in most formal and academic environments. The use of "IIII" on clocks, while interesting, does not replace the actual value "IV" holds in proper Roman numeral arithmetic.