Excel has two error detection functions that are almost identical: ISERR and ISERROR. Their syntaxes are identical:
ISERR(value) and ISERROR(value). They will both return True if the value throws an error. The difference is the ISERROR function will detect #N/A errors and ISERR won’t.
Excel formula: convert Roman numerals to regular Arabic numbers
Last year, I did a TikTok video blog post about Excel’s =ROMAN function (watch it here). It will convert any regular Arabic number to Roman.