A rope is several meters long, use up (1/2) of it for the first time, use up the remaining (1/2) for the second time, use up the remaining (1/2) for the third time, and use up the remaining (1/2) for the third time. There are 4 meters left. How long is this rope in meters?
一根绳子长若干米，第一次用去它的(1/2)，第二次用去剩下的(1/2)，第三次再用去剩下的(1/2)，还剩下4米．这根绳子原来长多少米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) * (1/2) * (1/2)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">4 / (1/8)</gadget>
<output>32</output>

<result>32</result>