Bob, a marathon runner, is preparing for a race.  He runs a total of 70 miles in the 3 days leading up to the race. On day one he runs 20 percent of the total miles and on day 2 he runs 50 percent of the remaining miles.  How many miles does he run on day three to complete the 70 miles?
Day 1: 70(.20)=
<gadget id="calculator">70*.20</gadget>
<output>14</output>
14 miles
70-14=
<gadget id="calculator">70-14</gadget>
<output>56</output>
56 miles remaining.
Day 2:56/2=
<gadget id="calculator">56/2</gadget>
<output>28</output>
28 miles
56-28=
<gadget id="calculator">56-28</gadget>
<output>28</output>
28 miles remaining.

<result>28</result>