John fills a 6 foot by 4 foot pool that is 5 feet deep.  It cost $.1 per cubic foot to fill.  How much does it cost to fill?
The pool has a base of 6*4=
<gadget id="calculator">6*4</gadget>
<output>24</output>
24 square feet.
So its volume was 24*5=
<gadget id="calculator">24*5</gadget>
<output>120</output>
120 cubic feet.
So it cost 120*.1=$
<gadget id="calculator">120*.1</gadget>
<output>12</output>
12 to fill the pool.

<result>12</result>