The original price of a mobile phone is 2,000 yuan, and it is sold at a 20% discount during the event. How much is the price reduction?
一部手机原价2000元，活动期间按八折销售，降价多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2_000 * (4/5)</gadget>
<output>1_600</output>

<gadget id="calculator">2_000 - 1_600</gadget>
<output>400</output>

<result>400</result>