The original price of a digital camera of a certain brand is 8,000 yuan, and now there is a promotional activity, and the price is reduced by 10%. On this basis, the mall returns 5% of the selling price in cash.
某品牌的数码相钒原价8000元，现进行促销活动，降价10%，在此基础上，商场又返还售价5%的现金，此时买这个品牌的数码相机应花多少钱？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

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

<gadget id="calculator">1 - (1/20)</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">8_000 * (9/10) * (19/20)</gadget>
<output>6_840</output>

<result>6_840</result>