A chicken farm sells 40% of the total number of chickens on the first day, and there are 1,200 chickens left. How many chickens are there in total?
某鸡场第一天卖出养鸡总只数的40%，还剩1200只鸡，养鸡场共养鸡多少只？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1_200 / (3/5)</gadget>
<output>2_000</output>

<result>2_000</result>