A jacket is 50 yuan, how much is the selling price after 30% off.
一件上衣50元，打7折后售价是多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">50 * (7/10)</gadget>
<output>35</output>

<result>35</result>