For the same reasons that numbers are so important to us today as follows:-
weights, measurements, stock control, accountancy, censuses, navigation, civil engineering, battle plans, addition, subtraction, division, multiplication .... etc
Roman numerals were used for writing numbers in ancient rome.
Roman numerals originated in ancient Rome in the country of Italy.
Rome is not traditionally spelled out using Roman numerals. Roman numerals are used to represent numbers in ancient Rome, not for spelling out words.
The numbers 1221 in Roman numerals is MCCXXI. Roman numerals is the numeric system that was used in ancient Rome and is still used on some clocks and watches.
Roman numerals
Ancient Rome.
Roman numerals were used for writing numbers in ancient rome.
Roman numerals originated in ancient Rome in the country of Italy.
Rome is not traditionally spelled out using Roman numerals. Roman numerals are used to represent numbers in ancient Rome, not for spelling out words.
It was started in ancient Rome.
The numbers 1221 in Roman numerals is MCCXXI. Roman numerals is the numeric system that was used in ancient Rome and is still used on some clocks and watches.
Julian Calendar and the roman numerals
Roman numerals
Nowadays it is MMCDX but in ancient Rome it was written quite differently
Today XIV represents 14 in Roman numerals but in ancient Rome it was XIIII
Nowadays it is MMXIV but in ancient Rome it once was MMXIIII
Roman numerals are how numbers were represented in Rome