Roman NumeralsDate: 06/05/97 at 09:08:16 From: e eddy Subject: Roman numerals Is there a reference table for writing Roman numerals? If so, what is it? If not, how does one write one million and ten thousand in Roman numerals? I have looked in math books, the dictionary, and searched the Internet. Most of the Internet search has turned up information on clocks and timepieces. The downloading is slow and this has taken a lot of time. A student asked me this question. I am using this search as a teaching tool to show students how to get information on the internet. This is a great web site. I plan to share it with others at my school. Date: 06/05/97 at 15:12:16 From: Doctor Jodi Subject: Re: Roman numerals Hi there! This is a great question. Here's what I found at the AskERIC site: http://ericir.syr.edu/Virtual/Lessons/Mathematics/Probability/PRB0006.html BACKGROUND: Roman numerals were developed around 500 B.C. at least partially from primitive Greek alphabet symbols which were not incorporated into Latin. Using predominantly addition, they are read from left to right. The symbol "I" for 1 was derived from one finger. Five fingers held up indicated five of whatever was being counted. The "V" then was the hand outstretched vertically with the space between the thumb and first finger forming the "V". Originally the Greek letter "X", or "chi", meant 50, but in monument transcriptions it is easy to trace the original symbol's change to "L", and "X" came to mean 10. Another theory for "X" is that ten 1's were written in a row, and then crossed out with an "X" to simplify counting. Then the "X" alone became a shorthand version of 10. Yet another idea is that "V" looks like the top half of "X", as 5 is half of 10. Other scholars think that "V" doubled with an upside-down "V" meant 5 times 2, or "X". "C", indicating 100, came from the Latin word "centum", a hundred. (Also century, centennial, etc.) "M" is from "mille", a thousand. Larger numbers, like 5,000, are shown by putting a small bar called a "vinculum" above the "V" symbol, indicating multiplication by 1,000. Until fairly recently a commonly used Roman numeral for 1,000 was "CI backwards C", derived from the Greek "phi", or "I" superimposed on "O". Half of this symbol, "I backwards C", led to "D" for 500, half of 1,000. Generally, decoding Roman numerals is very straightforward. The largest numeral is at the left, with descending numerals moving to the right. Numbers are added as you go, as seen in these examples: CCLXVII: 200 + 50 + 10 + 5 + 1 + 1 = 267 MMMCCLXXXI: 1,000 + 1,000 + 1,000 + 100 + 100 + 50 + 10 + 10 + 10 + 1 = 3,281 DCCXVII: 500 + 100 + 100 + 10 + 5 + 1 + 1 = 717 Rather than continuing to add 1's to make 4 ("IIII") or 9 ("VIIII"), subtraction was included in the computation of the numerals to simplify and shorten the resulting numbers. Therefore, 4 is shown "IV", or 5 minus 1. The smaller numeral BEFORE the larger one means subtract. "IX" is 9, or 10 minus 1. 40 is "XL", 50 minus 10; 90 is "XC", 100 minus 10; "CD" is 400, or 500 minus 100; and "CM" is 900, or 1,000 minus 100. Students can follow the principle that subtraction takes place ONLY when the smaller numeral is before the larger one, and involves 4 and 9 in various place values. Obviously, the cumbersome aspect of Roman numerals is one of the main reasons that they have been replaced by the Arabic system in our daily mathematical lives. Roman numerals remain important as a part of the world's cultural past, and a unique way to express numbers. REFERENCES: Most encyclopedias have at least some information on Roman numerals, and several books on Roman numerals are appropriate for students. Three suggestions: _Number Art - Thirteen 1 2 3's from around the world_, by Leonard Everett Fisher, published by Four Winds Press, NY, is a fairly sophisticated overview of world numerical systems. _Signs and Symbols Around the World_, by Elizabeth Helfman, published by Lothrop, Lee and Shepard Co, NY, has a chapter on numerals of many cultures. There is a very short section on Roman numerals, but a great deal of general information about counting and mathematics applications throughout the world. _Roman Numerals_, by David A.Adler, published by Thomas Y.Crowell Co, NY, is a much simpler book, but suitable for younger students. -Doctor Jodi, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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