Students participating in military training plan to start from school, walk 4.5 kilometers per hour, and arrive at the destination after 4 hours. If they walk 0.5 kilometers per hour, how many hours will it actually take to reach the destination?
同学们参加军训，计划从学校出发，每小时行4.5千米，经过4小时到达目的地，如果每小时多走0.5千米，实际需要几小时到达目的地？
<gadget id="calculator">4.5 + 0.5</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">4.5 * (4/5)</gadget>
<output>3.6</output>

<result>3.6</result>