Proposal for modifying gnucash to use exact quantities

Richard Wackerbarth
Tue, 25 Jul 2000 11:44:48 -0500

On Tue, 25 Jul 2000, John Hasler wrote:
> Bill Gribble writes:
> > Are there *any* places where correct record keeping requires one to keep
> > track of dollar values down to the 1/1000 of a dollar?
> Property tax rates are stated in mills, but the actual tax bills are always
> in dollars and cents.

Here in Texas, the tax rates are expressed in cents per $100 valuation which 
is 1/10 mill per dollar. But as you note, they always collect the amount 
rounded to 1/100 dollar.

I think that people are still confusing "amounts" and "prices".

For accounting, an amount is always an INTEGRAL number of something.
You can only add (and subtract) amounts that are expressed in the same 

Prices (exchange rates, conversion factors) are the ratio of two amounts.

Their primary use is to convert from one kind of amount to another.

An INTEGRAL number of onething is extended by the RATIONAL ratio of so many 
anothers per some number of onethings to yield an INTERGAL number of the 

Note that the display of a price is actually determined by determining the 
amount (of some display unit) that corresponds to the extension of a 
predetermined amount of the commodity being priced. Further, amounts may be 
displayed in terms of some (usually higher) multiple. The format of the 
display of the fractional part will depend upon the intended use and not the 
actual value.

It may be reasonable to treat each display strategy as a separate "object", 
especially if you allow those objects to inherit methods.