The original price of a piece of clothing is 80 yuan, how much is the price after a 20% discount?
一件衣服原价80元，打八折后的价钱是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 * (4/5)</gadget>
<output>64</output>

<result>64</result>