There are 56 students in Class 1 of Sixth Form. In the final exam, 15 of them were good, 6 of them passed, and the rest were all excellent. Seek the excellent rate.
六1班有学生56人，在期末考试中，15人良好，6人及格，剩下的人全是优秀，求优秀率．
<gadget id="calculator">56 - 15 - 6</gadget>
<output>35</output>

<gadget id="calculator">35 / 56</gadget>
<output>5/8 = around 0.625</output>

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

<gadget id="calculator">(5/8) * 1</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>