A product is 180 yuan, which is 20 yuan cheaper than the original price. How much is this product lower than the original price?
一件商品180元，比原来便宜了20元，这件商品比原来降低了百分之几？
<gadget id="calculator">180 + 20</gadget>
<output>200</output>

<gadget id="calculator">20 / 200</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>