There are 20 boys in a class, more than girls (1/4), how many fewer girls than boys?
某班男生20人，比女生人数多(1/4)，女生比男生少多少人．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">20 / (5/4)</gadget>
<output>16</output>

<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<result>4</result>