D = 500
C = 100
L = 50
X = 10
I = 1
DCXXIX = 500 + 100 + 2 ORI 10 + 10-1
600 + 20 + 9
DCXXIX = 629
DCCLX = 500 + 2 ORI 100 + 50 + 10
DCCLX = 700 + 60 = 760
XCX = 100 = 100 - 10 + 10