Xiaogang did 9 questions, but got 2 wrong, how much of the total number of questions did he get right?
小刚做了9道题，结果做错了2道，做对的题占总题数的多少
<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<result>7/9 = around 0.777778</result>