>>37130129No, it is just that using subtractions wasn't common during the imperial time.
The main god, Jupiter, was written as IVPPITER back then. Romans used to save space abbreviations and the common abbreviation for IVPPITER was IV.
In order to be clear then the number 4 was written as IIII and only during the middle ages it changed as IV, following the numerical rules that apply to the other numbers.
But since the number 4 was written IIII in sundials for a long time, clockmakers decided to keep it.
