If the Quantity Break is 10 and the total ordered quantity is 30, the number of
premiums for that order is 3. If the ordered quantity is not an exact multiple
of the break value specified in the discount schedule (say, 10), the quotient
of the integer division is taken and that many times the free item(s) are
applied. For example, for an ordered quantity between 31 to 39, three free
items are given.