The original price of "Interesting Mathematics Stories" is 25 yuan, and the current price is 20 yuan. The current price is the original price.
《趣味数学故事》原价25元，现价20元，现价是原价的多少．
<gadget id="calculator">20 / 25</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>