There are 30 boys and 21 girls in our class. What percentage of the whole class are boys?
我们班有男生30人，女生21人，男生占全班人数的几分之几？
<gadget id="calculator">30 + 21</gadget>
<output>51</output>

<gadget id="calculator">30 / 51</gadget>
<output>10/17 = around 0.588235</output>

<result>10/17 = around 0.588235</result>