There are 2,400 chickens and ducks in a farm. The ratio of chickens to ducks is 8:2. After selling some chickens, the ratio of chickens to ducks is 2:1. How many chickens were sold?
一个养殖场有鸡和鸭共2400只，其中鸡与鸭的只数比是8：2，卖掉一些鸡后，鸡与鸭的只数比是2：1，卖掉了多少只鸡？
<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">8 / 10</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2_400 * (4/5)</gadget>
<output>1_920</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2_400 * (1/5) * 2</gadget>
<output>960</output>

<gadget id="calculator">1_920 - 960</gadget>
<output>960</output>

<result>960</result>