My mother's total income last month was 1300 yuan. According to the relevant national tax law: the portion exceeding 800 yuan has to pay 5% personal income tax. How much tax should my mother pay this month?
妈妈上月的总收入是1300元，按国家有关税法的规定：超过800元的部分要缴纳5%的个人所得税，妈妈这个月应缴纳多少元的税金．
<gadget id="calculator">1_300 - 800</gadget>
<output>500</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">500 * (1/20)</gadget>
<output>25</output>

<result>25</result>