Xiaojun was swimming in the swimming pool. The lane was 128.4 meters long. He swam back and forth in the lane. How many meters did he swim in total?
小军在游泳池游泳，泳道长128.4米，他在泳道内游了一个来回，共游了多少米？
<gadget id="calculator">128.4 * 2</gadget>
<output>256.8</output>

<result>256.8</result>