Why are there no zero in Roman numerals?

Answer 1

In our system, based on tens, we add a zero to the end of a number to increase its value by ten. So 1 x ten becomes 10 and 10 times ten becomes 100 etc. We use zeros within numbers to indicate that there are no numbers in that column, so 102 means there is 1 x 100, no x 10s and 2 x units. The Romans had a different system were they used different symbols to denote tens, hundreds and thousands etc. So in Roman numerals 1 x ten is X and X times ten is C. The Romans simply missed out numerals which weren't needed so 102 in Roman numerals was CII (100 + 2). As they didn't add a zero to the end of numbers or use one within numbers they had no need to invent a symbol to represent zero. During the Middle Ages monks, who still wrote in Latin and still used Roman numerals, introduced the numeral N to represent zero (based on the Latin word Nulae, meaning nothing)