the number four in ancient rome is usually written as IIII instead of IV

Actually, that's not the case. In ancient Rome, the number four was almost always written as "IV" and not "IIII". The use of Roman numerals "IV" for four is consistent with the rules of the Roman numeral system.

The misconception that "IIII" was used instead of "IV" might come from a few isolated examples or historical variations. However, they do not represent the standard or typical practice in ancient Rome.

Here are some key points:

1. Standard Practice: Roman numerals were developed in ancient Rome and followed certain rules. For numbers greater than 3, you generally added symbols rather than subtracted. So, "IV" (one less than five) became the standard way to represent four.

2. Historical Consistency: Most surviving examples of ancient Roman inscriptions, monuments, and texts use "IV" to represent the number four. This consistency demonstrates that "IV" was the accepted form.

3. Exceptions: While there may be a few rare instances where "IIII" appears, they are not representative of the broader usage in ancient Rome. These could be due to regional variations or individual mistakes.

4. Later Adoption: In later periods and different regions, you might see "IIII" used in some contexts, such as on older European clocks. But this does not reflect the predominant practice in ancient Rome.

5. Understanding Context: It's important to consider the broader context when encountering variations in historical texts or artifacts. The occasional use of "IIII" does not change the fact that "IV" was the standard and widely accepted representation of the number four in ancient Rome.

In summary, while there might be a few exceptions, the number four was almost always represented by "IV" in ancient Rome. The idea that "IIII" was commonly used in ancient Rome is not accurate based on the vast majority of evidence from inscriptions, monuments, and texts. "IV" remains the standard and correct representation of four in the Roman numeral system.