Why should we teach Roman numerals?

In my local paper this morning, I read about how a North Carolina state commission plans to recommend changes to our teaching standards for mathematics. One of the topics that they want to bring back: Roman numerals. Why? According to my exhaustive 30 seconds of Internet research, the only practical applications of Roman numerals are: I) understanding Super Bowl numbering, and II) reading the time on old-fashion clocks.

But I don't need convincing. I believe that there are other advantages of teaching Roman numerals. The main lesson is this: the world has not always revolved around "base 10" numbering, and actually it still doesn't today. Having the ability to express numbers in other forms helps us to understand history, passage of time, technology, and even philosophy*.

In the popular media, binary (base 2) is famous for being "the language of computers". That may be so, but binary is not usually the language of computer programmers. When I was a kid, I spent many hours programming graphics on my TI 99/4A computer. I became proficient in translating decimal to hexadecimal (base 16) to binary -- all to express how the pixels would be drawn on the screen and in what color. Due to lack of practice and today's availability of handy tools and higher-level programming languages, I have since lost the ability to calculate all of these in my head. I also lost the ability to solve any Rubik's Cube that I pick up -- there go all of my party tricks.

But the SAS programming language retains many fun math tricks, including the ability to express numbers in many different ways, instantly. Here's an example of one number expressed six (or 6 or VI or 0110) different ways.

data _null_;
x = 1956;
put / 'Decimal: ' x=best12.;
put / 'Roman: ' x=roman10.;
put / 'Word: ' x=words50.;
put / 'Binary: ' x=binary20.;
put / 'Octal: ' x=octal10.;
put / 'Hexadecimal: ' x=hex6.;
run;

The output:

Decimal: x=1956
Roman: x=MCMLVI
Word: x=one thousand nine hundred fifty-six
Binary: x=00000000011110100100
Octal: x=0000003644
Hexadecimal: x=0007A4

You might never need some of these number systems or SAS formats in your job, but knowing them makes you a more interesting person. If nothing else, it's a skill that you can trot out during cocktail parties. (I guess I attend different sorts of parties now.)

* For example, the number 'zero' has not always been with us. Introducing it into our numbering system allows us to think about 'nothing' in ways that earlier societies could not.