My grandma's family has 28 hens and 17 roosters. If each hen lays an egg every day, how many eggs did my grandma's family lay in total in April?
姥姥家养了28只母鸡，17只公鸡，如果每只鸡每天下一个鸡蛋，姥姥家四月份一共下了多少个鸡蛋？
<gadget id="calculator">28 * 30</gadget>
<output>840</output>

<result>840</result>