John sends his son to prep school.  It cost $20,000 per semester.  There are 2 semesters in the year.  How much does it cost to send the kid to 13 years of school?
It cost 20000*2=$
<gadget id="calculator">20000*2</gadget>
<output>40_000</output>
40,000 a year.
So it cost 40,000*13=$
<gadget id="calculator">40000*13</gadget>
<output>520_000</output>
520,000.

<result>520_000</result>