A class of 50 people is doing a math problem, and 10 people get it wrong, what is the correct rate of this problem?
全班50人做一道数学题，10个人做错，这道题的正确率是多少．
<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<gadget id="calculator">40 / 50</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) * 1</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>