Xiao Jun participated in the quick calculation competition, got 18 questions right, and got 2 questions wrong. What is his correct rate in this game?
萧军参加速算比赛，做对了18题，错了2题．他这次比赛的正确率是多少？
<gadget id="calculator">18 + 2</gadget>
<output>20</output>

<gadget id="calculator">18 / 20</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(9/10) * 1</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>