The number of boys in a class is more than the number of girls (1/5), how many girls account for the whole class
某班男生人数比女生人数多(1/5)，女生占全班人数的多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5) + 1</gadget>
<output>11/5 = around 2.2</output>

<gadget id="calculator">1 / (11/5)</gadget>
<output>5/11 = around 0.454545</output>

<result>5/11 = around 0.454545</result>