The price of a product is 180 yuan, which is 20 yuan lower than the original price. How much is the reduction?
一件商品售价180元，比原价降低了20元，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>