There are 301 boxes of eggs and duck eggs, of which there are 156 boxes of eggs. How many boxes are there of duck eggs?
鸡蛋和鸭蛋共有301箱，其中鸡蛋有156箱，鸭蛋有多少箱？
<gadget id="calculator">301 - 156</gadget>
<output>145</output>

<result>145</result>