During the New Year's Day, a sweater originally priced at 100 yuan in a shopping mall was only sold at 85 yuan.
元旦期间，一家商场原价100元的毛衣只售85元，算一算，这种毛衣降价多少．
<gadget id="calculator">100 - 85</gadget>
<output>15</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>