The number of chickens and rabbits is the same, and their legs add up to 54. How many chickens are there?
鸡和兔的数量相同，它们腿加起来共有54条．鸡有多少只．
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">54 / 6</gadget>
<output>9</output>

<result>9</result>