Understanding Roman Numbers
| Field | Documentation: old-fashioned clocks, library bookshelves, monumental inscriptions |
| Went Obsolete | Gradually during 20th century |
| Made Obsolete By |
- Use of Arabic numbers
- Digital clocks
- Online literature instead of journals on library shelves
| Knowledge Assumed | Knowledge of Roman numbers, eg I,II, III, IV, V, VI, .... XLII, ... |
| When useful | Reading old-fashioned clocks, finding the right volume in leather-bound runs of journals in libraries, reading dates on buildings and monuments |
Roman numerals:
- I = 1
- V = 5
- X = 10
- L = 50
- C = 100
- D = 500
- M = 1000
A possible mnemonic to remind one of the order of letters is (from highest to lowest value):
My Dear Cat Loves Xtra Vitamins Intensely
Usage, in brief:
Small number before larger number is subtracted from it: IV is 5-1 = 4
Small number after larger number is added to it: VI=5+1=6
So MDCXLVIII is 1000 + 500 + 100 + (50-10) + 5 + 1 + 1 + 1 = 1648
For more information see Wikipedia article at http://en.wikipedia.org/wiki/Roman_numerals