Little A ran 4 back and forth on a straight track, running a total of 728 meters. How long is this runway in meters?
小A在一条直跑道上跑了4个来回，一共跑了728米．这条跑道长多少米？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">728 / 8</gadget>
<output>91</output>

<result>91</result>