Mary and Jimmy start running from the same spot, but in opposite directions. Mary runs at 5 miles per hour and Jimmy runs at 4 miles per hour. What is the distance between them after 1 hour?
In 1 hour, Mary will have traveled 5 miles/hour * 1 hour = 
<gadget id="calculator">5*1</gadget>
<output>5</output>
5 miles.
In 1 hour, Jimmy will have traveled 4 miles/hour * 1 hour = 
<gadget id="calculator">4*1</gadget>
<output>4</output>
4 miles.
Since they are running in opposite directions, the distance between them will be 5 miles + 4 miles = 
<gadget id="calculator">5+4</gadget>
<output>9</output>
9 miles.

<result>9</result>