There are 50 students in Class 1, 30 of whom participate in extracurricular interest groups. How many percent more people participate in extracurricular interest groups than those who don't?
六1班有50人，其中有30人参加课外兴趣小组．参加课外兴趣小组的人数比没参加的人数多百分之几？
<gadget id="calculator">50 - 30</gadget>
<output>20</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<gadget id="calculator">10 / 20</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>