A bottle of Coca-Cola sells for 4 yuan now, and it will be 20% off during the festival. How much is the original price per bottle?
一瓶可口可乐现在卖4元，节日期间一律打八折，原价每瓶售价多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

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

<result>5</result>