Principal payments for declining balance loans dont add up to loan amount

From Aliya:

When you create a loan schedule for declining balance loans, if you sum up the
principal amount for each payment, it is off from the expected total principal
amount by a few decimal places (eg. 10000.4 instead of 10000). This is also a
concern for Nag and he wants this research to understand if this is some
expected adjustment rule or rounding error (I think rounding error). Again, he
needs to know this so that they can determine if they can account for this in
their accounting system at the end of each month when they move to declining
balance loans.

Note that the total principal shown on the loan details page is correct - just
different from when you add the sum of the prinicipal payments.