The fifth grade has 20% fewer students than the sixth grade, and by what percentage is the sixth grade more than the fifth grade?
五年级的学生人数比六年级的学生人数少20%，六年级的学生人数比五年级的学生人数多百分之几？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>