The price of a kind of electric fan has been reduced twice, the first price reduction (1/5), the second price reduction (1/10), the current price is the original ((())/(())).
一种电扇先后两次降价，第一次降价(1/5)，第二次降价(1/10)，现在的价钱是原来的((())/(()))．
<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>