Some clocks, chapters of some books, chemistry, plays, etc.
W existed in the "medieval roman numerals", they were different from the modern roman numerals we know and use today. W was 800, in modern roman numerals that would be DCCC.
Yes
yes
I use roman numerals in math
Modern Romans use Roman numerals about as infrequently as the rest of the western world. Arabic numerals was much easier to use for all purposes, so the old Roman numerals are used only in formal notices like foundation stones, and often, not even then. In ancient times, before Arabic numerals were introduced to Europe, the ancient Romans used Roman numerals for all activities that required counting or arithmetic. That included commercial transactions, accounting (such as it was), calendars, etc.
By medieval rules on the use of Roman Numerals this is invalid. However in classical times the use of such numbers was commonplace, so consider MDCDX a nonstandard arrangement of Roman numerals for 1910 = 1000+(500-100)+500+10.
The Roman numeral system was used during ancient Roman times, but use of the system continued long after the Roman empire declined. In the 14th century, Roman numerals were slowly replaced by Hindu-Arabic numbers.
In todays modern usage of Roman numerals: 95 = XCV
Some use roman numerals because some doesn't know numbers, so instead it is roman numerals.
Well over 2000 years. However the Roman Numerals we use today are not the Roman Numerals that the Romans used.As the Romans used them there was no ordering: IV & VI were both six, four could only be written as IIII, etc.It was monks in the middle ages that introduced modern Roman Numerals as a shorthand form.
Some countries only use Roman Numerals, so they use it a lot.
We still use Roman numbers today. One place where you often see Roman numbers is on a clock face. We generally make use of less of Roman Numerals.3604262 in roman numerals is MMMDCMMMMCCLXII.