The original price of the pen is 10 yuan, after 15% discount, how much is the current price?
钢笔原价10元，打八五折后，现价是多少元？
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">10 * (17/20)</gadget>
<output>17/2 = around 8.5</output>

<result>17/2 = around 8.5</result>