A frog can eat about 864 pests in 12 days. According to this calculation, how many pests can a frog eat in a month (30 days)?
一只青蛙12天大约可以吃864只害虫．照这样计算，一只青蛙一个月(30天)大约可以吃多少只害虫？
<gadget id="calculator">864 / 12</gadget>
<output>72</output>

<gadget id="calculator">72 * 30</gadget>
<output>2_160</output>

<result>2_160</result>