Mr. Wang earned 2,800 yuan in manuscript fees for writing books. According to the regulations: the part after deducting the 800 yuan in manuscript fees is subject to personal income tax at a rate of 20%, so how much personal income tax should Mr. Wang pay?
王老师写书所得稿费2800元，按规定：扣除稿费中800元后的部分按20%的税率缴纳个人所得税，那么王老师应缴纳个人所得税多少元．
<gadget id="calculator">2_800 - 800</gadget>
<output>2_000</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2_000 * (1/5)</gadget>
<output>400</output>

<result>400</result>