If an owl can kill about 480 mice a year, how many mice can it kill on average every month?
一只猫头鹰，如果一年约能消灭480只老鼠，那么它平均每个月约能消灭多少只老鼠？
<gadget id="calculator">480 / 12</gadget>
<output>40</output>

<result>40</result>