If boys in a class account for 40% of the class, how much more girls than boys?
某班男生占全班的40%，那么女生比男生多多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / (2/5)</gadget>
<output>1/2 = around 0.5</output>

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