A piece of fabric is (3/5) meters long, (1/4) meters are used up, how many meters are left?
一块布料长(3/5)米，用去了(1/4)米，还剩多少米．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/5) - (1/4)</gadget>
<output>7/20 = around 0.35</output>

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