A circular runway is 200 meters long. If a warning sign is erected every 10 meters, how many warning signs are needed?
一个圆形的跑道长200米，如果每隔10米竖一道警示牌，共需多少道警示牌．
<gadget id="calculator">200 / 10</gadget>
<output>20</output>

<result>20</result>