The snail and the tortoise race. When the snail is 78 cm away from the finish line, the tortoise is only 28 cm away from the finish line. Who is temporarily ahead? How many decimeters ahead?
蜗牛和乌龟赛跑，蜗牛距终点还有78厘米时，乌龟距终点只有28厘米，谁暂时领先？领先多少分米？
<gadget id="calculator">78 - 28</gadget>
<output>50</output>

<gadget id="calculator">50 / 10</gadget>
<output>5</output>

<result>5</result>