Xiaoli bought a "Children's Encyclopedia" with a 20% discount, which is 5 yuan cheaper than the original price. What is the original price of this book?
小丽买了一本打八折的《儿童百科全书》，比原价便宜5元，这本书的原价是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 / (1/5)</gadget>
<output>25</output>

<result>25</result>