Yumin Primary School set up a factory. It originally planned to bind 21,600 exercise books in 12 days, but actually bound 360 more books per day than the original plan. How many days did it actually take to complete the production task?
育民小学校办厂，原计划12天装订21600本练习本，实际每天比原计划多装订360本．实际完成生产任务用了多少天？
<gadget id="calculator">21_600 / 12</gadget>
<output>1_800</output>

<gadget id="calculator">1_800 + 360</gadget>
<output>2_160</output>

<gadget id="calculator">21_600 / 2_160</gadget>
<output>10</output>

<result>10</result>