Here is an example to illustrate — during the month of June there were 3 calls to an inbound domestic number:
Call 1–9 minutes
Call 2–15 minutes
Call 3–45 minutes
Suppose that the cost per minute is USD $0.01, which is charged in 10-minute chunks at USD $0.10 per chunk. The overall domestic minutes usage for June is (9+15+45) = 69 minutes total. This time is billed by chunking the minutes as follows:
There are six full 10-minute chunks. This bills you for six chunks at the cost of $0.10 per chunk.
The 9-minute call is considered as an incomplete chunk and disregarded from the bill.
The invoice will contain an Inbound Domestic Inbound SKU per 10 minutes, Quantity = 6, Charge USD $0.60. This charge is less than the original per minute price for the same number of minutes, USD $0.69, due to the disregarded 9-minute call.