The price of a piece of clothing is 80 yuan. If it is sold at a 20% discount, how much less will be sold.
一件衣服售价80元，如果打八折出售，少卖了多少元．
<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">80 * (1/5)</gadget>
<output>16</output>

<result>16</result>