Class 6 has 30 boys and 20 girls. By what percentage are boys more than girls?
六1班有30名男生，20名女生．男生比女生多百分之几？
<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>