A wire is (14/15) meters long, if (7/12) meters are used up, how many meters are left?
一根铁丝长(14/15)米，用去(7/12)米，还剩多少米．
<gadget id="calculator">14 / 15</gadget>
<output>14/15 = around 0.933333</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">(14/15) - (7/12)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>