There is a 15-meter-long ribbon, used up (14/15), how many meters are left?
有一根15米长的彩带，用去了(14/15)，还剩下多少米．
<gadget id="calculator">14 / 15</gadget>
<output>14/15 = around 0.933333</output>

<gadget id="calculator">1 - (14/15)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">15 * (1/15)</gadget>
<output>1</output>

<result>1</result>