The original price of a piece of clothing is 120 yuan, and now it is sold at a 20% discount, which is how much cheaper than the original price.
一件衣服原售价120元，现打8折出售，比原价便宜多少元．
<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">120 * (1/5)</gadget>
<output>24</output>

<result>24</result>