An Ancient Roman Method of Counting Still Used Today Roman Numerals An Ancient Roman Method of Counting Still Used Today ©2013 HappyEdugator

History The Romans, who were active traders and merchants, needed to invent a system to keep up with numbers. They had to have a way to record the large amounts of goods and money being exchanged. ©2013 HappyEdugator

History They developed a type of additive numeral system where each character has a value independent of its position in its representation. In other words, unlike our system which is based on the Arabic number system, there is no place value and there is no number for zero. ©2013 HappyEdugator

Modern Usage Roman numerals are not used as much today as they once were. However, you may see them in books as copyright dates, chapter headings, and on pages preceding the main body of a book. They are also used to number main headings in outlines. Additionally, Roman numerals are used on some clock faces, after names of successive rulers (Henry VIII), and after children with successive family names. They may be found on names of ships, on the numbering of annual events, and even on gravestones. ©2013 HappyEdugator

The Roman Numerals The Romans used letters to represent their numbers. They are as follows: I = 1 V = 5 X = 10 L = 50 C = 100 D = 500 M = 1000 ©2013 HappyEdugator

How To Read Roman Numerals Read from left to right and add together: For example- I= 1, II = 2, III = 3 In Ancient Rome, IIII=4, but this was changed in the Middle Ages to IV, which is one before five, make writing numbers easier. Likewise, in Rome VIIII = 9, but 9 is now written as IX, or one before ten. The highest value numbers will be on the left. So, 157 would be CLVII, because C=100, L=50, V=5 and II = 2. Add these together to get 157. ©2013 HappyEdugator

Practice Try to figure out the Roman numerals on the next slides. Don’t worry, if you make a mistake, you can do over! Click on the answer you believe is correct. ©2013 HappyEdugator

LXXIII A. 523 B.73 C. 93 ©2013 HappyEdugator

Sorry! That is not right. Do over! ©2013 HappyEdugator

You are correct! LXIII = 50+20+3 =73 Remember: L=50; X=10; III=3 ©2013 HappyEdugator

2.DCXXXIV A. 634 B. 7124 C. 5524 ©2013 HappyEdugator

Sorry! That is not right. Do over! ©2013 HappyEdugator

You are correct! DCXXXIV= 500+100+30+4= 634 ©2013 HappyEdugator

3. CCLXIX A. 1509 B.269 C. 559 ©2013 HappyEdugator

Sorry! That is not right. Do over! ©2013 HappyEdugator

You are correct! CCLXIX = 100+100+50+10+9=269 ©2013 HappyEdugator

4. MCMLX A. 1949 B.2015 C. 1960 ©2013 HappyEdugator

Sorry! That is not right. Do over! ©2013 HappyEdugator

You are correct! MCMLX = 1000+900+50+10=1960 ©2013 HappyEdugator

5. MCMLXXXIV A. 1935 B.1984 C. 1976 ©2013 HappyEdugator

Sorry! That is not right. Do over! ©2013 HappyEdugator

You are correct! MCMLXXXIV = 1000+900+50+30+4= 1984 ©2013 HappyEdugator

Hint: Roman numerals are easy to figure out if you remember it’s just like a code. Memorize what the letters stand for and you will know that you just read the numbers from left to right and add them up! ©2013 HappyEdugator