A sweater is now priced at 200 yuan, which is 20% lower than the original price, and how much is it lower than the original price.
一件毛衣现在售价200元，比原来降低了20%，比原来降低了多少元．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">200 / (4/5)</gadget>
<output>250</output>

<gadget id="calculator">250 - 200</gadget>
<output>50</output>

<result>50</result>