The original price of a certain computer mainframe is 4,000 yuan, but now it is sold at 3,200 yuan, which is much cheaper than the original price.
某种电脑主机原价是4000元，现在售价是3200元，现价比原价便宜了多少．
<gadget id="calculator">4_000 - 3_200</gadget>
<output>800</output>

<gadget id="calculator">800 / 4_000</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>