A rope is 4 meters long, first use up (5/8) and then use up (3/8) meters, how many meters are left.
一根绳子长4米，先用去(5/8)，再用去(3/8)米，还剩多少米．
<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 - (5/8)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">4 * (3/8)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(3/2) - (3/8)</gadget>
<output>9/8 = around 1.125</output>

<result>9/8 = around 1.125</result>