The original price of a sweater is 180 yuan, how much is it after 30% off.
一件毛衣原价180元，打七折后是多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">180 * (7/10)</gadget>
<output>126</output>

<result>126</result>