Xiaoming's father's monthly salary is 2,840 yuan. According to the relevant regulations on personal income tax, 20% of the personal income tax must be paid on the part exceeding 2,000 yuan. So how much income tax should Xiaoming's father pay on his monthly salary?
小明爸爸的月工资是2840元，按照个人所得税的有关规定，超过2000元部分要缴纳20%的个人所得税，那么小明爸爸月工资应缴纳所得税多少元．
<gadget id="calculator">2_840 - 2_000</gadget>
<output>840</output>

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

<gadget id="calculator">840 * (1/5)</gadget>
<output>168</output>

<result>168</result>