1. Roman Numerals Students will convert Arabic numerals to Roman numerals and vice versa Students will write numbers using the Roman numeral system

2. When do you use Roman numerals?

3. Roman Numerals up to 3999 Arabic1510501005001000 RomanIVXLCDM Mneumonic for Roman Numerals

4. Roman Numerals 4000 and above

5. Combine symbols to make Roman numerals Read left to right If the small numeral comes after a big numeral, add it (add as much as three) –VIII V + I + I + I = 5 + 1 + 1 + 1 –XV X + V = 10 + 5 –LX L + X = 50 + 10 –MDCCCLXXXVIII 1000 + 500 + 100 + 100 + 100 + 50 + 10 + 10 + 10 + 5 + 1 + 1 + 1 = 1888 Arabic1510501005001000 RomanIVXLCDM

6. Practice adding Roman numerals *Break up Roman and Arabic numerals by places 1750 1000700500= MMLXI MM--LXI= 3253 = DCXXXV = 86 = Arabic1000500100 50105 1 RomanMDC LXV I

7. Combine symbols to make Roman numerals Arabic1510501005001000 RomanIVXLCDM Read left to right If the small numeral comes before a big numeral, subtract it (subtract only one symbol at a time, one place value away) –IX -I + X = -1 + 10 –XIV X + IV = 10 + (-1 + 5) –CD -C + D = -100 + 500 –MCMXCIX M CM XC IX 1000 + (-100 + 1000) + (-10 + 100) + (-1 + 10) = 1999

8. Combine symbols to make Roman numerals Arabic1510501005001000 RomanIVXLCDM Quick overview of Roman numerals which subtract the symbol on the left from the symbol on the right: IV(-1 + 5 = 4)IX(-1 + 10 = 9) XL (-10 + 50 = 40)XC(-10 + 100 = 90) CD (-100 + 500 = 400)CM(-100 + 1000 = 900) VVL ≠ XL (simplify!) LC ≠ L (simplify!) IIX ≠ VIII (you can only subtract one symbol at a time) IC ≠ XCIX (you can only subtract from one place value away)

9. Practice subtracting Roman numerals *Break up Roman and Arabic numerals by places 1904 100090004= MMXLI MM--XLI= 3493 = MCMXL = 89 = Arabic1000500100 50105 1 RomanMDC LXV I

10. Combine symbols to make Roman numerals It was easier to carve numerals like quattuor and novem as IV and IX instead of IIII and VIIII. VIIII vs. VIII can be hard to distinguish. What is this number? VIIIII

11. XI-XX XI XII XIII XIV XV XVI XVII XVIII XIX XX undecim duodecim tredecim quattuordecim quindecim sēdecim septendecim duodēvīgintī undēvīgintī vīgintī

12. XXI-XXX? XXI__________vīgintī ūnus/-a/-um XXII__________vīgintī duo/-ae/-o XXIII__________vīgintī trēs/tria XXIV__________vīgintī quattuor XXV__________vīgintī quinque XXVI__________vīgintī sex XXVII__________vīgintī septem XXVIII__________vīgintī octō / duodētrīgintī XXIX__________vīgintī novem / undē trīgintī XXX__________trīgintā

13. L, C, D, M Lquīnquāgintā Ccentum Dquīngentī/-ae/-a Mmille MMduo mīlia

14. XL - MM XL L LX LXX LXXX XC C CI D M MM MMMCMXCIX quadrāgintā quīnquāgintā sexāgintā septuāgintā octōgintā nōnāgintā centum centum ūnus quīngentī/-ae/-a mille duo mīlia trēs mīlia nongentī nōnāgintā et novem

15. MMMCMXCIX trēs mīlia nongentī nōnāgintā et novem MMMCMXCIX MMM = 1000 + 1000 + 1000 CM = 1000 – 100 XC = 100 – 10 IX = 10 – 1 3000 900 90 +9 3999

16. Roman Numeral Practice MMXIV__________2014 MCMXCIX__________1999 DCCLIII__________753 BCE XCVII__________97 MCMLXXXIV__________1984 MCDXCII__________1492

17. Roman Numeral Practice CDLIII __________ CMXCVI__________ MMXI __________ CIX__________ MCMXLIV__________ MMMCDXCI__________