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Roman Numerals. Lesson 3. What are Roman numerals?. There are 7 Roman numerals. I = 1 V = 5 X = 10 L = 50 C = 100 D = 500 M = 1,000. 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).
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Roman Numerals Lesson 3
What are Roman numerals? • There are 7 Roman numerals. • I = 1 • V = 5 • X = 10 • L = 50 • C = 100 • D = 500 • M = 1,000
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)
How do Roman numerals work? • To subtract, place a smaller numeral before a larger one. • 9 • IX (I – X) • 4 • IV (I – V)
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.
Subtraction • I • V • X • L • C • D • M I X C
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 • 100+20+5 • C+XX+V • CXXV
Let’s practice! • 53 • 178 • 29 • 543 • 2011 • 50 + 3 LIII • 100 + 70+ 8 CLXXVIII • 20 + 9 XXIX • 500+40+3 DXLIII • 2,000 + 10 + 1 MMXI