A piece of floral cloth (9/4) meters, (1/4) is used up, how many meters are left.
一块花布(9/4)米，用去(1/4)，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">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(9/4) * (3/4)</gadget>
<output>27/16 = around 1.6875</output>

<result>27/16 = around 1.6875</result>