| Field | Documentation: old-fashioned clocks, library bookshelves, monumental inscriptions |
| Went Obsolete | Gradually during 20th century |
| Made Obsolete By |
| 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, Determining the edition of some events (i.e. Movie Sequels, Sporting Events such as Super Bowls and Olympics) |
Roman numerals:
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
