A business hall needs to pay business tax at 20% of the turnover, and then pay education surtax at 7% of the sales tax. The education surcharge is the amount of the turnover.
某营业厅要按营业额的20%缴纳营业税，再按营业税的7%缴纳教育附加税，教育附加税是营业额的多少．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">7 / 100</gadget>
<output>7/100 = around 0.07</output>

<gadget id="calculator">(1/5) * (7/100)</gadget>
<output>7/500 = around 0.014</output>

<result>7/500 = around 0.014</result>