Roman Numerals

The history of Roman numerals began back in the 8th to 9th century BC, approximately the same time as the founding of ancient Rome around Palantine Hill. The system is somewhat flawed as there is no representation for zero (0). This didn’t prevent Roman intellectuals and architects from building a great empire.

• I = 1
• V = 5
• X = 10
• L = 50
• C = 100
• D = 500
• M = 1000

A mnemonic is a phrase that you can memorize more easily than a list of numbers:

I Value Xylophones Like 
Cows Do Milk

Add numbers with larger digits first:

XI = 10 + 1 = 11
VII = 5 + 1 + 1 = 7
III = 1 + 1+ 1 = 3
CLXI = 100 + 50 + 10 + 1 = 161

Treat numbers with smaller digits first as subtraction:

IV = 5 – 1 = 4
IX = 10 – 1 = 9
XL = 50 – 10 = 40
XC = 100 – 10 = 90

If you need to, divide a number into groups of digits to understand it better. Always make sure you catch any “subtraction problems” with a smaller digit in front of a larger one, and include both the digits into the same group.

MCMXCIX = M + CM + XC + IX
1000 + 900 + 90 + 9 = 1999

The Super Bowl football games are always designated as Roman numerals – the 2022 Super Bowl in Los Angeles is LVI

LVI = 56

This makes calculating a movie like the “Wizard of OZ” a breeze:

M=1000 + CM = 1000 – 100 = 900
+ XXX = 30 = IX = 9
=1000 +900 +30 +9
=1939 (the year the film was released)

MMVIX = 1000 + 1000 +
5 + (10 – 1)

2014 – the year of this episode of Top Gear

MCMLXXVI = 1000 + 900
+ 50 + 10 + 10 + 6

1976 – The year I graduated from High School

Sometimes there will be a bar above a letter to represent a very large number, if so multiply by 1000:

X with a “-” above it means 10,000
V with a “-” above it means
5000
IX with a “-” above it means 9000