The original price of a book is 21.5 yuan. Now sell at 40% off the original price, how much is the current price?
一本画册的原价是21.5元．现在按原价的六折出售，现价是多少元？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">21.5 * (3/5)</gadget>
<output>12.9</output>

<result>12.9</result>