Xiaoqing went to Xinhua Bookstore to buy a copy of "Interesting Mathematics".
小晴去新华书店买一本《趣味数学》，原价15元，现打八折出售，小晴应付多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">15 * (4/5)</gadget>
<output>12</output>

<result>12</result>