Latex does not directly support displaying upper and lower case Roman numbers, but can be achieved through custom numerics.
Define the new command \ rmnum and \ rmnum to display upper and lower case Roman numerals.
Usage: \ rmnum {number}, \ rmnum {number}
\ Makeatletter
\ Newcommand {\ rmnum} [1] {\ romannumeral #1}
\ Newcommand {\ rmnum} [1] {\ expandafter \ @ slowromancap \ romannumeral #1 @}
\ Makeatother
InArticleAdd the above four lines in the Introduction area, and then you can use the command \ rmnum {number} And rmnum {number} in the body to display the upper and lower case roman numerals respectively.
The following is a simple example of the use of Roman numerals.
\ Documentclass {Article}
% New commands defined in the introduction section
\ Makeatletter
\ Newcommand {\ rmnum} [1] {\ romannumeral #1}
\ Newcommand {\ rmnum} [1] {\ expandafter \ @ slowromancap \ romannumeral #1 @}
\ Makeatother
\ Begin {document}
% Command usage
\ Rmnum {1}, \ rmnum {5}, \ rmnum {55 }\\
\ Rmnum {1}, \ rmnum {5}, \ rmnum {55}
\ End {document}