A coat is priced at 400 yuan after a price reduction of 100 yuan. How much is the current price lower than the original price? How many
一件大衣，降价100元后的售价是400元．现价比原价降低了百分之几？多少
<gadget id="calculator">400 + 100</gadget>
<output>500</output>

<gadget id="calculator">100 / 500</gadget>
<output>1/5 = around 0.2</output>

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