Two trains, A and B, depart from Beijing and Shanghai at the same time. Train A travels 100 kilometers per hour, and train B travels 108 kilometers per hour. The two trains meet after 7 hours. How many kilometers is the railway between Beijing and Shanghai?
甲、乙两列火车同时从北京和上海相对开出，甲火车每小时行100千米，乙火车每小时行108千米，7小时后两车相遇．北京与上海之间铁路长约多少千米？
<gadget id="calculator">100 + 108</gadget>
<output>208</output>

<gadget id="calculator">208 * 7</gadget>
<output>1_456</output>

<result>1_456</result>