A piece of iron wire is 15 meters long. After cutting off (1/5), how many meters are left?
一根铁丝长15米，剪去(1/5)后，还剩下多少米．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">15 * (4/5)</gadget>
<output>12</output>

<result>12</result>