Steve writes a letter every 3rd day to his friend.  He spends 20 minutes writing the letters.  It takes 10 minutes to write 1 page.  He also writes a long letter at the end of the month which he puts more thought into.  It takes twice as long per page but he spends 80 minutes writing.  How many pages does he write a month?
He writes 30/3=
<gadget id="calculator">30/3</gadget>
<output>10</output>
10 normal letters.
Each letter is 20/10=
<gadget id="calculator">20/10</gadget>
<output>2</output>
2 pages.
So that is 2*10=
<gadget id="calculator">2*10</gadget>
<output>20</output>
20 pages.
His long letter takes 2*10=
<gadget id="calculator">2*10</gadget>
<output>20</output>
20 minutes per page.
So it is 80/20=
<gadget id="calculator">80/20</gadget>
<output>4</output>
4 pages.
So he writes 20+4=
<gadget id="calculator">20+4</gadget>
<output>24</output>
24 pages.

<result>24</result>