Jan buys 1000 feet of cable.  She splits it up into 25-foot sections.  She gives 1/4 of that to a friend.  She then puts half of the rest in storage. How much does she keep on hand?
She gets 1000/25=
<gadget id="calculator">1000/25</gadget>
<output>40</output>
40 sections.
She gives away 40/4=
<gadget id="calculator">40/4</gadget>
<output>10</output>
10 sections.
So she keeps 40-10=
<gadget id="calculator">40-10</gadget>
<output>30</output>
30 sections.
She keeps 30/2=
<gadget id="calculator">30/2</gadget>
<output>15</output>
15 sections on hand.

<result>15</result>