A rope is 12 meters long, cut off (3/4), and the full length ((())/(())) remains, how many meters are left.
一根绳子长12米，剪去(3/4)，还剩下全长的((())/(()))，还剩多少米．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">12 * (1/4)</gadget>
<output>3</output>

<result>3</result>