Uncle Li's family has 42 chickens, three times the number of ducks, and half the number of geese. How many fewer ducks than chickens?
李叔叔家养鸡42只，是养鸭只数的3倍，鹅的只数是鸭的一半．鸭比鸡少多少只？
<gadget id="calculator">42 / 3</gadget>
<output>14</output>

<gadget id="calculator">42 - 14</gadget>
<output>28</output>

<result>28</result>