A marathon is 26 miles.  He can run the first 10 miles in 1 hour.  For the remaining miles he runs at 80% that pace.  How long does the race take?
There are 26-10=
<gadget id="calculator">26-10</gadget>
<output>16</output>
16 miles left for the rest of the race.
He runs 10*.8=
<gadget id="calculator">10*.8</gadget>
<output>8</output>
8 miles per hour.
So it takes him 16/8=
<gadget id="calculator">16/8</gadget>
<output>2</output>
2 hours.
So in total it takes 1+2=
<gadget id="calculator">1+2</gadget>
<output>3</output>
3 hours.

<result>3</result>