A kind of soybean salad oil, the original price is 50 yuan, the current price is 40 yuan, what percentage is the price reduction?
一种大豆色拉油，原价是50元，现价是40元，降价百分之几？
<gadget id="calculator">50 - 40</gadget>
<output>10</output>

<gadget id="calculator">10 / 50</gadget>
<output>1/5 = around 0.2</output>

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