Roman Numerals

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Roman Numerals

• By Amber K. Wozniak

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What are Arabic Numerals?

• Briefly, Arabic numeration is the technical term
  for the numerals that we use.
• The numeral figures include 1, 2, 3, 4, 5, 6, 7,
  8, 9, and the 0 (zero).

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What are Roman Numerals?

• Roman numeration is a base ten system. This is
  shown in the way people count by fingers (there
  are 10 fingers to two hands).
• Roman numerals are the letters I, V, X, L, C, D,
  and M combined in specific orders to represent
  numbers.

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Whats so Great about Roman Numerals?

• Roman numerals are found on clock faces,
  buildings, some gravestones, and the pages that
  preface chapters of a book.
• Knowing how to write out Roman numerals will help
  you understand addition and subtraction better.

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The Figures

• I 1
• V 5
• X 10
• L 50
• C 100
• D 500
• M 1000
• Something extra Adding a line above any figure
  other than I means that you multiply that numeral
  by 1,000

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Rules of Roman Numerals

• Never put more than three of the same figure
  together.
• Placing a numeral to the left of a larger
  numeral, like IV, it means that one is taken
  away, or subtracted, from five.
• It is not IIII, but IV
• A numeral subtracted can only be two place values
  away from the larger numeral.
• You can not take 1 away from 50 to get 49. You
  must take 40 (50-10) and combine it with 9 (10-1)

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Example 1

• Converting Arabic numerals into its Roman
  numeral, using addition properties
• 3 III (111)
• 6 VI (51)
• 57 LVII (50511)
• 231 CCXXXI (1001001010101)

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Example 2

• Converting Arabic numerals into Roman numerals,
  using rules for subtraction
• 4 IV (5-1 or 1 taken away from 5)
• 9 IX (9-1 or 1 taken away from 10)
• 40 XL (50-10 or 10 taken away from 50)
• 199 CXCIX (100100-1010-1)

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Practice converting Roman and Arabic numerals
from one to the other

• Roman numerals to Arabic form
• Arabic form to Roman numerals

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Web Sites to visit for more practice or any extra
information you would like to look at

• Nova Roma
• Math Forum
• Legion XXIV
• Cool Math 4 Kids
• Roman Numerals Quiz
• Learning Roman Numerals