Xiao Ming participated in a swimming competition, and swam 4 back and forth on the 25-meter-long swimming lane. Do you know how many meters Xiao Ming participated in?
小明参加游泳比赛，在25米长的泳道上游了4个来回，你知道小明参加的是多少米的比赛吗？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">25 * 8</gadget>
<output>200</output>

<result>200</result>