It is zero because it's not needed in the Roman numeral system.
The number 50 is represented by the Roman numeral L
The number 2100 written in Roman numerals is MMC
The number 169 can be written in Roman numerals as CLXIX
The Roman numeral which represented the number 50 was called quinquaginta and it was written as L
The number 1485 written in Roman numerals is MCDLXXXV
The number 57 written in Roman numerals is LVII
The number 52 in Roman numerals is written as "LII".
The number 1450 is written in roman numerals as MCDL.
The number 4 is written in Roman numerals as IV
The number 64 in roman numerals is written as LXIV.
The number 23 in Roman numerals is written as XXIII.
Written as a Roman numeral, the number 6 would be expressed as VI. The letter V indicates the number 5 and the letter I indicates the number 1. When the letter I is written after the letter V in Roman numerals it indicates that 1 should be added to the number written before it.