The distance between the starting point and the finishing point of the tortoise and the hare is 10,000 meters. The speed of the rabbit is five times that of the tortoise. They set out from the same place at the same time, and soon the rabbit left the tortoise far behind, so the rabbit triumphantly lay down under a big tree and fell asleep. The tortoise has been persevering and running towards the finish line. When the rabbit woke up, he found that the tortoise had surpassed the rabbit by 5,000 meters, so he rushed to catch up. When the tortoise reached the finish line, the rabbit was still 100 meters away from the finish line. Ask: The rabbit sleeps How many meters did the tortoise walk?
龟兔赛跑，起点到终点的距离为10000米．兔子的速度是乌龟的5倍，它们从同一地点同时出发，不久兔子就把乌龟远远地甩在后面，于是兔子便得意洋洋地躺在一棵大树下面睡起觉来．乌龟一直在坚持不懈，持之以恒地向终点跑着，兔子一觉醒来，发现乌龟已经反超兔子5000米了，这才慌忙追赶上去，当乌龟到达终点时，兔子还距终点100米，问：兔子睡觉时，乌龟走了多少米？
<gadget id="calculator">10_000 - 100</gadget>
<output>9_900</output>

<gadget id="calculator">9_900 / 5</gadget>
<output>1_980</output>

<gadget id="calculator">10_000 - 1_980</gadget>
<output>8_020</output>

<result>8_020</result>