Xiao Ming took several exams, the last time he wanted to take the exam with a score of 97, so that the average score reached 90, but he only got 73 points, and the average score was 87. How many times did Xiao Ming take the exam?
小明参加若干次考试，最后一次他想考97分，使平均成绩达到90分，但考下来只得了73分，平均成绩是87分，小明参加了几次考试？
<gadget id="calculator">97 - 73</gadget>
<output>24</output>

<gadget id="calculator">90 - 87</gadget>
<output>3</output>

<gadget id="calculator">24 / 3</gadget>
<output>8</output>

<result>8</result>