A jacket is 150 yuan, how much is the price after 20% off.
一件上衣150元，8折后的价钱是多少元钱．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">150 * (4/5)</gadget>
<output>120</output>

<result>120</result>