If there are more boys than girls (1/2), then there are fewer girls than boys ((())/(())).
男生人数比女生多(1/2)，那么女生人数比男生少((())/(()))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) - 1</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / (3/2)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>