Codex Romanus: The Guide
Deciphering the Ancient Code
Roman Relics challenges Year 5 students to master the number system of the Roman Empire. Unlike our modern place-value system (where position determines value), Roman numerals use a combination of adding and subtracting fixed symbols. This game builds fluency in reading years (like MMXXV) and decoding complex values up to 1000 (M).
The Seven Symbols
I
1
V
5
X
10
L
50
C
100
D
500
M
1000
Rule of Addition
When a symbol appears after a larger (or equal) symbol, ADD it.
VI = 5 + 1 = 6
CXX = 100 + 10 + 10 = 120
Rule of Subtraction
When a symbol appears before a larger symbol, SUBTRACT it.
IV = 5 - 1 = 4
CM = 1000 - 100 = 900
Year 5 National Curriculum
- Read Roman numerals to 1,000 (M) and recognise years written in Roman numerals.
