A rope is (4/5) meters long, how many meters are left after cutting (1/5)
一根绳子长(4/5)米，截去(1/5)后，还剩多少米
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<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">(4/5) * (4/5)</gadget>
<output>16/25 = around 0.64</output>

<result>16/25 = around 0.64</result>