The original price of a book is 22 yuan, how much is the price of 30% off?
一本书原价22元，打七折的价钱是多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">22 * (7/10)</gadget>
<output>77/5 = around 15.4</output>

<result>77/5 = around 15.4</result>