In order to welcome the "October" Golden Week, all the products are sold at a reduced price (1/5). A coat is sold for 640 yuan after the price is reduced. How much is the original price of this coat?
商场为迎接"十一"黄金周，所有的商品降价(1/5)销售．一件大衣降价后卖640元，这件大衣原价多少元？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">640 / (4/5)</gadget>
<output>800</output>

<result>800</result>