The exchange rates are fixed and are offical Euro exchange rates. The invoice total, before conversion, equals the sum of the line items. After conversion they differ by a penny or so. I need to be sufficiently precise so that they are equal after conversion.

A parallel example: my brother noted that at a particular Washington State sales tax rate, it was cheaper by a penny to buy two single Big Gulps rung up separately than it was to buy them as a combined transaction. So whenever he had to buy two, he'd always buy one, pay, then buy the second one.

This is the real world, and it's accepted practice. Don't attempt the impossible. {grin}

-- Randal L. Schwartz, Perl hacker

You cannot always balance to the penny when you map values from one currency to another and it's considered fair accounting practice to simply note that and move on.

But note that noting that usually implies that the lost round-off amount is accounted for in a special "accumulate round-offs" account in the general ledger. I know we have such a beast at work. Otherwise (I hypothesise) you open yourself up to salami attacks.

--

g r i n d e r

D'oh! Its impossible! Perlcgi has an epiphany. That's the key insight! Thank you very much Randal. {grins back in humble appreciation}