Daily life · Roman Empire Daily
Roman numerals have no symbol for zero. The concept simply wasn't part of the system.
Deep dive
Roman numerals are additive and subtractive (IV, IX) but lack a positional zero. Romans handled calculations with counting boards and the abacus. The zero as a number entered European mathematics much later via Indian and Arabic sources.
Source: Standard histories of mathematics; e.g., Ifrah, 'The Universal History of Numbers.'