Uncle Li's family has 42 chickens, and the number of ducks is half of that of chickens. How many chickens and ducks does Uncle Li's family raise?
李伯伯家养了42只鸡，养鸭的只数是鸡的一半．李伯伯家一共养鸡、鸭多少只？
<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">42 + 21</gadget>
<output>63</output>

<result>63</result>