If the price of a commodity is 250 yuan, and it is sold at a 20% discount, what is the selling price?
一件商品的标价是250元，打八折出售，则卖出价格为多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">250 * (4/5)</gadget>
<output>200</output>

<result>200</result>