In order to promote sales, a certain electrical appliance store decided to sell a TV with an original price of 3,500 yuan at a discount of 20% (that is, 80% of the original price). In this way, how much less should a TV be sold?
某电器商城为了促销，决定将原价3500元一台的电视机打八折(即原价的80%)出售，这样，一台电视机要少卖多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3_500 * (4/5)</gadget>
<output>2_800</output>

<gadget id="calculator">3_500 - 2_800</gadget>
<output>700</output>

<result>700</result>