The original price of a coat is 100 yuan, and the current price is 80 yuan. How much is the price reduction from the original price?
一件上衣原价100元，现价80元，比原价降价几分之几？
<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>