A chickadee can eat about 640 pests in 4 days. According to this calculation, how many pests can a half-month eat? (Calculation of An 15 for half a month)
一只册山雀4天大约能吃害虫640只，照这样计算，一只半个月大约能吃多少只害虫？(半个月安15计算)
<gadget id="calculator">640 / 4</gadget>
<output>160</output>

<gadget id="calculator">160 * 15</gadget>
<output>2_400</output>

<result>2_400</result>