The original price of "Andersen's Fairy Tales" is 12 yuan, and the current promotional price is 9 yuan. How much is the current price cheaper than the original price?
《安徒生童话》每本原价12元，现在的促销价是9元，现价比原价便宜百分之几？
<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>