>>Great info!
>>I'll be using the field for currency (ex GST values) which require 3 decimal places to be sufficiently accurate under Australia law. It certainly saves some space in the tables compared to N(13,3).
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>I am curious, how many decimals do you use in normal situations?
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We use 3 dec for ex tax calcs and 2 for inc tax figures. We get no rounding problems at the moment. We have to calculate GST (currently 10%) on each line item to "maximum precision" and then round at the invoice total level to state a total GST. That's the tax dept rules.
With the type of problem you reminded me of we'll have to be careful to check that our reports are still accurate. The accounts people hate losing one or two cents here or there :-).
But in essence we SHOULD be more accurate with 4 decimals than 3 provided we are only doing add-ups and subtractions. Most other maths involving $$ usually is with integers such as Quantity.
If this works out well we extend the usage to our many other tables involved in "currency"