A piece of cloth is (9/4) meters long, how many meters are left after (1/4) meters are used up?
一块布长(9/4)米，用去(1/4)米后，还剩多少米．
<gadget id="calculator">9 / 4</gadget>
<output>9/4 = around 2.25</output>

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

<gadget id="calculator">(9/4) - (1/4)</gadget>
<output>2</output>

<result>2</result>