They're numbers. Hence the term 'numeral'.
You is a word, not a letter. If you mean the letter U, in Roman numerals it is written V and stands for 5.
V is the Roman numeral equivalent to 5
This is not a valid roman numeral!
It is: 5 = V as a Roman numeral
LXXVI is the Roman numeral for 76.
The Roman numeral of DXIII is equivalent to 513
You mean Roman Numeral? It is XVI
if you mean what number the letter change in. well the answer is 100. 100 is D
The roman numeral M represents the number 1000.
The Roman numeral CCLXVI represents the number 266
The Roman numeral CXXXVI represents the number 136
The Roman numeral MCMXC represents the number 1990