Math Basics / Nursing
Learning Centre
Roman Numerals
Roman numerals use letters of the alphabet to represent number values as shown in
the table below. To translate numbers into Roman numerals, write down the meaning of
each digit in Roman numerals using the rules below. Notice that each place (tens,
hundreds, etc.) gets a different set of letters.
I
V
X
L
C
D
M
1
5
10
50
100
500
1000
The full Roman numeral is written digit by digit.
o If the digit is 0, don’t write anything.
o If the digit is 1 or 5, write the letter from the table based on the
meaning of the digit.
o If the digit is anything other than 1 or 5, we put letters together to
make up the number.
• If the digit is a four or a nine, the Roman system uses
subtraction. Four is one less than five (or 1 before 5), the
Romans write: IV. Ninety is 10 before 100: XC.
• For all other numbers (2, 3, 6, 7, 8) the Roman system uses
addition. Thirty is three tens: XXX. Eight is five plus three ones:
VIII. (Generally you want to write the number with the least
amount of numerals).
Let’s look at 354. Each place value (hundreds, tens, ones) must be translated into
Roman numerals. The “3” in 354 means 300. The Romans would write three 100’s:
CCC. The “5” means 50, so write L. The “4” means 4 ones, so write: IV. The number
354 would be “300, 50, 4” or “CCC, L, IV”, but without spaces: CCCLIV.
Roman numerals can also be written with lower case letters, so 354 could also be
written cccliv. Be careful! An uppercase I (1) can often look like a lower case l (50).
To translate Roman numerals into familiar numbers, separate them by place values,
then translate each place value. Use the stair step below to help:
M
thousands
D C
hundreds
L X
tens
V I
ones
Consider MMDCCXCVI.
© 2013 Vancouver Community College Learning Centre.
Student review only. May not be reproduced for classes.
AuthoredbybyEmily
Darren
Rigby
Simpson
1) Every time we “go down a stair” we break the Roman numeral up: MM - DCC XC - VI.
2) Translate each section of the numeral separately. Sections that go up a stair
represent a digit of 4 or 9. If the numeral skips a stair, that represents a 0.
MM = 1000 + 1000 = 2000
DCC = 500 + 100 + 100 = 700
XC = 10 before 100 = 90
VI = 5 + 1 = 6
So MMDCCXCVI = 2796.
EXERCISES
A. Write in Roman numerals.
1. 7
7. 256
2. 40
8. 199
3. 3000
9. 204
4. 600
10. 2897
5. 31
11. 1485
6. 1030
12. 2108
B. Write as Arabic numbers (1, 2, 3…)
1. DI
7. cix
2. CD
8. mcdlxiv
3. LIV
9. II
4. xvi
10. mdcxlvi
5. MMCCXXII
11. mmmdccxxi
6. DVI
12. mmdxcvi
SOLUTIONS
A. (1) VII (or vii…) (2) XL (3) MMM (4) DC (5) XXXI (6) MXXX (7) CCLVI
(8) CXCIX (9) CCIV (10) MMDCCCXCVII (11) MCDLXXXV (12) MMCVIII
B. (1) 501 (2) 400 (3) 54 (4) 16 (5) 2222 (6) 506 (7) 109 (8) 1464
(9) 2 (since LL isn’t a Roman numeral) (10) 1646 (11) 3721 (12) 2596
© 2015 Vancouver Community College Learning Centre.
Student review only. May not be reproduced for classes.
2