1. Roman Numerals!
Sept. 24, 2013

2. What are Roman numerals?
There are 7 Roman numerals.
I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1,000

3. How do Roman numerals work?
To add, place one or more numerals of equal or lesser value after a numeral. 3
III (I+I+I) 6
VI (V+I)
105
CV (C+V)

4. How do Roman numerals work?
To subtract, place a smaller numeral before a larger one. 9
IX (I – X) 4
IV (I – V)

5. Subtraction There are some rules about subtraction.
I, X and C (1, 10, 100) are the only numerals that can be subtracted.
I can only be subtracted from V and X.
X can only be subtracted from L and C.
C can only be subtracted from D and M.

6. Subtraction I V X L C D M I X C

7. How to write Roman numerals
Break down a number into its places: tens, hundreds, thousands
Write each section in Roman numerals
Arrange the results left-to-right. 46
40 + 6
XL + VI
XLVI
125
C+XX+V
CXXV

8. 53 178 29 543 2013 Let’s practice! 50 + 3 LIII 100 + 70+ 8 CLXXVIII
XXIX
DXLIII
2, MMXIII

9. Let’s Practice!
Try the year you were born!