...
Rounding Digits = This is the number of Rounding Digits selected on the Rate Deck page for the Termination Customer Rate Deck associated to the Termination Customer Trunk Group that received the call. The example below show 4 Rounding Digits.
...
Term Cost = CEILING((orig_rate * (orig_billed_duration / 60))* POWER(10, Rounding Digits),1) / POWER(10, Rounding Digits)
...