sprinter ran 4 round trips on a straight track for a total of 800 meters. How long is this straight track?
短跑选手在一段直跑道上跑了4个来回，共跑了800米，这段直跑道有多长？
<gadget id="calculator">800 / 4</gadget>
<output>200</output>

<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<result>100</result>