A sixth-grade labor team had to help the school-run factory paste 2,640 cartons, but actually 240 were pasted in 3 days. According to this calculation, how many days will it take for the remaining cartons?
六年级一个劳动小组要帮助校办厂糊2640个纸盒，实际3天就糊了240个．照这样计算，剩下的纸盒还要多少天？
<gadget id="calculator">2_640 - 240</gadget>
<output>2_400</output>

<gadget id="calculator">240 / 3</gadget>
<output>80</output>

<gadget id="calculator">2_400 / 80</gadget>
<output>30</output>

<result>30</result>