A train travels from A to B at 80 kilometers per hour and arrives in 10 hours. If the speed of the train increases to 100 kilometers per hour, how many hours can it arrive in advance?
一列火车从甲地开往乙地，每小时行80千米，10小时到达，如果火车每小时速度提高到100千米，可以提前几小时到达？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">80 * (1/10)</gadget>
<output>8</output>

<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<result>2</result>