There are 480 chickens and ducks in the farm. After half of the chickens are sold, the remaining chickens and ducks are the same. How many chickens were there in the farm?
养殖场有鸡和鸭共480只，卖出一半鸡后，剩下的鸡和鸭同样多．养殖场原来有鸡多少只？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) + 1</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">480 / (3/2)</gadget>
<output>320</output>

<result>320</result>