When a computer is sold, it is 10% lower than the original price of 4000 for the first time, and 10% lower for the second time. How much is the current price of this computer?
一种电脑销售时，第一次比原价4000降低了10%，第二次又降低了10%．这种电脑现价多少元？
<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">4_000 * (9/10) * (9/10)</gadget>
<output>3_240</output>

<result>3_240</result>