It is known that Keyou Coke originally sold for 5 yuan, and it will be discounted by 20% during the festival. Now, the price of each bottle is much less than the original price.
已知可有可乐原来卖5元，节日期间一律打八折，现在每瓶售价比原来少多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 * (1/5)</gadget>
<output>1</output>

<result>1</result>