There are 30 boys and 27 girls in class one of the fifth grade. How many girls account for the whole class
五年级一班有男生30人，女生27人，女生占全班人数的多少
<gadget id="calculator">30 + 27</gadget>
<output>57</output>

<gadget id="calculator">27 / 57</gadget>
<output>9/19 = around 0.473684</output>

<result>9/19 = around 0.473684</result>