This document compares Roman numerals to decimal numbers, showing how each place value in the decimal system corresponds to a symbol in the Roman numeral system. It provides examples of how to write numbers in Roman numerals up to 999,999 by combining symbols for thousands, hundreds, tens and ones, such as DC L mV ccc xx i representing 654,321.

1. Roman Digits vs. Decimal Places
10^5 10^4 10^3 10^2 10^1 10^0
C X m c x i
CC XX mm cc xx ii
CCC XXX mmm ccc xxx iii
CD XL mV cd xl iv
D L V d l v
DC LX Vm dc lx vi
DCC LXX Vmm dcc lxx vii
DCCC LXXX Vmmm dccc lxxx viii
CM XC mX cm xc ix
Example:
DC L mV ccc xx i = 654,321