There are 21 boys and 20 girls in Class 1 of the fifth grade. What percentage of the whole class are girls?
五年级一班有男生21人，女生20人，女生占全班人数的几分之几？
<gadget id="calculator">21 + 20</gadget>
<output>41</output>

<gadget id="calculator">20 / 41</gadget>
<output>20/41 = around 0.487805</output>

<result>20/41 = around 0.487805</result>