It is hoped that there will be 40 boys and 20 girls in the sixth grade of elementary school. How many percent are girls less than boys?
希望小学六年级有男生40人，女生20人，女生比男生少百分之几？
<gadget id="calculator">40 - 20</gadget>
<output>20</output>

<gadget id="calculator">20 / 40</gadget>
<output>1/2 = around 0.5</output>

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