# Significant figures

Judy Ann Brown (judyann@dimacs.rutgers.edu)
Fri, 4 Jul 1997 17:10:04 -0400

Hi

I found an interesting site it's called the Universal Currency Converter.
http://www.xe.net/currency/

There is also an interactive curency table at:
http://www.xe.net/currency/table.htm

This site is updated daily.

The following excerpt from the FAQ's at
might generate a few lesson ideas.

Or you might just want to check out the value of your money if you plan to visit
Hong Kong since it has been in the news so much of late.

Judy

2. Why do the number of decimal places in the Interactive Currency Table vary
from currency to currency?

This is not an error, nor is it a bug; it is math. Each currency value we
get has a different,
limited number of significant figures. (Significant figures are not simply
decimal places.)
When performing the multiplication and division necessary to convert
currencies, the
precision of the result is entirely dependent on the precision of the
numbers that make it up.
Specifically, the result of the conversion can never have more significant
figures
than any of the currency values used to calculate it.

For example, Turkish Lira (TRL) are regularly specified with only three
significant figures
-- so no value in a Currency Table generated with Turkish Lira can have
more than three
significant figures. This is why generated currency tables do not have a
consistent number of
decimal places.

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Judy Ann Brown
judyann@forum.swarthmore.edu
judyann@dimacs.rutgers.edu
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