If (3/4) of the 16-meter-long rope is used up, how many meters are left?
16米长的绳子，用去它的(3/4)，还剩下多少米．
<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">16 * (1/4)</gadget>
<output>4</output>

<result>4</result>