A car is driving from place A to place B, planning to travel 80 kilometers per hour and arrive in 5 hours. Actual driving 100 kilometers per hour, how many hours before the actual arrival?
一辆汽车从甲地开往乙地，计划每小时行驶80千米，5小时到达．实际每小时行驶100千米，实际提前几小时到达？
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">80 * (1/20)</gadget>
<output>4</output>

<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<result>1</result>