Li Bing participated in a math competition, got 18 questions right and got 2 questions wrong. Find Li Bing's correct rate.
李兵参加数学竞赛，做对了18题错了2题．求李兵的正确率．
<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>