The turnover of Tiantian Supermarket last month was 4.2 million yuan, and business tax was paid at 5% of the turnover. How much business tax should the supermarket pay last month?
天天超市上个月的营业额是420万元，按营业额的5%缴纳营业税，该超市上个月应缴纳营业税多少万元．
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">420 * (1/20)</gadget>
<output>21</output>

<result>21</result>