The original length of a rope after being folded twice is ((())/(())).
一根绳子对折2次后的长度是原来的((())/(()))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * (1/2)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>