The distance between Naughty's house and Xiaoxiao's house is 840 meters. The two started from home at the same time and walked toward each other. Naughty walked 70 meters per minute, and Xiaoxiao walked 50 meters per minute. When they met, how far did Xiaoxiao walk?
淘气家到笑笑家的路程是840米，两人同时从家出发，相向而行，淘气每分钟走70米，笑笑每分钟走50米，他们相遇时，笑笑走了多远？
<gadget id="calculator">70 + 50</gadget>
<output>120</output>

<gadget id="calculator">840 / 120</gadget>
<output>7</output>

<gadget id="calculator">7 * 50</gadget>
<output>350</output>

<result>350</result>