In the Roman numeral system, is the standard representation for the number 4 . It is formed by placing the symbol I (1) before the symbol V (5), which signifies the subtraction of 1 from 5 (5 - 1 = 4). The Logic of IV: Subtractive Notation
The Roman system is primarily additive, but it utilizes a "subtractive principle" to make certain numbers more concise. Instead of writing four individual strokes (IIII), the system allows for placing a smaller numeral to the left of a larger one to indicate subtraction. This rule is also applied to other numbers, such as for 9 (10 - 1) and XL for 40 (50 - 10). The Mystery of IIII vs. IV iv roman numerals
While is the standard in modern mathematics and literature, you will frequently see IIII used on clock faces and in historical documents. There are several theories for this variation: Roman numerals - The National Archives In the Roman numeral system, is the standard