The bearing factory planned to process 1800 bearings, and processed 840 bearings in the first 7 hours. According to this calculation, how many hours will it take to complete this batch of tasks?
轴承厂计划加工1800个轴承，头7个小时加工了840个，照这样计算，完成这批任务还要多少小时？
<gadget id="calculator">1_800 - 840</gadget>
<output>960</output>

<gadget id="calculator">840 / 7</gadget>
<output>120</output>

<gadget id="calculator">960 / 120</gadget>
<output>8</output>

<result>8</result>