Transcript Document

EQ: How do you read and write Roman Numerals?
Where do you see Roman
Numerals?
• Super Bowl & Olympics
• Movies
• Clocks
• Outlines
• Books
• Names (Henry VIII)
• Roman numerals are part of the ancient Roman number
system that remains in use today. The history of Roman
numerals dates back to 1st millennium BC when they were
used to record numbers in stone, art and coins.
• Roman numerals add a classic style that Arabic numerals
cannot. Arabic (decimal) numbers ( 0 to 9 ) were
introduced into Europe about 900 AD and were adopted
quickly for their convenience and mathematical ease of use.
Let’s Learn the Roman
Numerals…
• I = one
• C = 100
• V = five
• D = 500
• X = ten
• M = 1,000
• L = fifty
There isn’t a symbol for zero.
The Rules for Writing Roman
Numerals
• The letters should be arranged from largest to
smallest.
– 1510 is written MDX, largest to smallest
• Only powers of ten can be repeated.
• Don’t repeat a letter more than three times in a
row.
– 100 is written C, not XXXXXXXXXX (too many
repeats)
Rules Continued
• Numbers can be written using subtraction.
• If you place any smaller number in front of a
larger number it symbolizes subtraction.
• For example, IV=4. It is really saying that 5 - 1
equals 4.
– Only powers for ten (I, X, C) can be subtracted.
– I can only be subtracted from V or X
Practice
• 515 = ?
• 39 = ?
• 1005 = ?
• 32 = ?
• 9= ?
Answers
• 515 = DXV
• 39 = XXXIX
• 1005 = MV
• 32 = XXXII
• 9= IX
Adding Roman Numerals
• Write down the two numbers you are adding right
next to each other
• Rearrange the letters so they start with the largest
and end with the smallest.
• Then start combining similar letters.
• Check you answer by adding the Arabic numbers.
Now Let’s Try Adding
Problem
1. 23 + 58
Answer to the Adding Problem
Step 1.
Step 2.
Step 3.
Step 4.
Step 4.
Step 5.
Step 6.
Step 7.
Step 8.
23 + 58
XXIII + LVIII
XXIIILVIII
LXXVIIIIII
IIIIII = VI
LXXVVI
VV = X
LXXXI = 81
23 + 58 = 81
Roman Numeral Number
I
1
V
5
X
10
L
50
C
100
D
500
M
1000
REALLY BIG NUMBERS!
If there is a line under the Roman Numeral “V, X, L, C, D, or
M” it means to add 3 zeros (multiply it by 1,000).
V would mean 5,000.
VIV
IXLII
Now try these:
1.
2.
3.
4.
5.
XXXVI
XL
XVII
DCCLVI
MCMLXIX
Click on the number that matches the
Roman Numeral.
1.LXIII
A. 53
B. 63
C. 113
OOPS! Try again!
You are correct!
LXIII = 50+10+3 = 63
Remember:
L=50; X=10; III=3
2.DCXXIV
A. 624
B. 1624
C. 5524
OOPS! Try again!
You are correct!
DCXXIV= 500+100+20+4=
624
3. CCL
A. 150
B. 250
C. 550
OOPS! Try again!
You are correct!
CCL = 100+100+50=250