Xiao Ming's father received a labor fee of 3,000 yuan, of which 2,500 yuan is tax-free, and the rest is taxed at a rate of 20%. How much is the total tax on this labor fee?
小明的爸爸得到一笔3000元的劳务费用，其中2500元是免税的，其余部分要按20%的税率缴税，这笔劳务费用一共要缴税多少元？
<gadget id="calculator">3_000 - 2_500</gadget>
<output>500</output>

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

<gadget id="calculator">500 * (1/5)</gadget>
<output>100</output>

<result>100</result>