The original price of a book is 12 yuan, how much is the price of the 20% discount?
一本书原价12元，打八折的价钱是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">12 * (4/5)</gadget>
<output>48/5 = around 9.6</output>

<result>48/5 = around 9.6</result>