The last step of a calculation problem should be divided by 10, but a careless student mistakenly multiplied by 10 in the last step. The answer he got is 500. What is the correct answer to the original question?
一道计算题的最后一步应除以10，但一个粗心的学生在最后一步却错误地乘以10了，他得出的答案是500，原题正确答案应是多少．
<gadget id="calculator">500 / 10</gadget>
<output>50</output>

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

<result>5</result>