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

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 XL + VI XLVI C+XX+V CXXV

Let’s practice! LIII CLXXVIII XXIX DXLIII 2, MMXI