This may sound like a stupid question, but is there a real reason to make
the monthly amount (in the case above, 16.66 or 16.67) be restricted to 2
decimal places (obviously corresponding with pennies)? If there's a termed
discount involved with an account, then the customer isn't going to be
paying $16.67 (or 16.6666667)--they're going to be paying the full term
amount of 200.0x.
So in the case above, the normal monthly rate could really be $20.000000 and
the annual discounted rate could be $16.666667 (which is quite a bit
different from 16.67 when calculating an annual total). Nothing at all
would ever come out different with non-termed-discounts, but those that are
affected by termed discounts have a lot more room to allow the admin to
tweak the totals, so the customer woulnd't see "Amount Due: $200.04" (or
$199.92) -- it'd be $200.00 (currently not possible because of the monthly
I'm just bouncing ideas around. Maybe I've been in the realm of
science/engineering too long and am used to deeper precission...