The original price of a computer is 4,000 yuan, and it is now on sale with a 20% discount. What is the price?
一台电脑原价4000元，现打八折出售，售价是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">4_000 * (4/5)</gadget>
<output>3_200</output>

<result>3_200</result>