Roman Numerals
Here are the properties that apply to Roman Numerals.
1. Additive Property
If A symbol of greater value comes before a symbol of lesser value, add.
Ex.
The Symbol I,X,C, and M can be repeated at most three times.
III = 1+1+1=3
XXX = 10+10+10=30
CCC = 100+100+100=300
MMM = 1,000+1,000+1,000=3,000
2.Subtractive Property
If a symbol lesser value comes before a symbol of greater value, subtract.
Ex.
IV = 5-1 = 4
IX = 10-1 = 9
XL = 50-10 = 40
XC = 100-10 = 90
CD = 500-100 = 400
CM = 1,000-100= 900
I is used only before and after V and X. It can also be used after all other symbols. V,L and D are not used before symbols of greater value.
3.Multiplicative Property
When a horizontal bar is written above a symbol. the value of the symbol is multiplied by 1,000.
Ex.
__
V = 5 x 1,000= 5,000
__
IX = 9 x 1,000 = 9,000
More bars over a symbol or symbols show larger numbers.
= 5 x 1,000 x 1,000 x 1,000 = 5,000,000
= 5 x 1,000 x 1,000 x 1,000 =5,000,000,000
Note: A horizontal bar above a symbol is called Vinculum
