There are 320 chickens in a farm, and there are 50 fewer ducks than chickens. How many chickens and ducks are there in this farm?
某饲养场养鸡320只，鸭比鸡少50只．这个饲养场养鸡和鸭一共多少只？
<gadget id="calculator">320 - 50</gadget>
<output>270</output>

<gadget id="calculator">270 + 320</gadget>
<output>590</output>

<result>590</result>