Master Li processes a batch of parts, plans to process 30 per hour, and can complete the task in 8 hours. The actual processing is 10 more per hour than the original plan, how many hours can the task be completed in advance?
李师傅加工一批零件，计划每小时加工30个，8小时可以完成任务．实际每小时比原计划多加工10个，可以提前几小时完成任务？
<gadget id="calculator">30 + 10</gadget>
<output>40</output>

<gadget id="calculator">8 / 40</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 * (1/5)</gadget>
<output>6</output>

<gadget id="calculator">8 - 6</gadget>
<output>2</output>

<result>2</result>