There is a kind of clothes in the store, the price is 100 yuan, which is 20% cheaper than the original price, how much cheaper than the original price?
商店有一种衣服，售价100元，比原价便宜了20%，比原来售价便宜多少元？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">100 / (4/5)</gadget>
<output>125</output>

<gadget id="calculator">125 - 100</gadget>
<output>25</output>

<result>25</result>