The opening ceremony of Mingde Primary School was held in the auditorium. The seats in the auditorium are 7 rows, each row has 126 seats. Now there are 25 seats vacant. How many people attended the opening ceremony?
明德小学在大礼堂举行开学典礼，礼堂座位是7排，每排有126个位置．现在位置空出了25个，一共有多少人参加这个开学典礼？
<gadget id="calculator">126 * 7</gadget>
<output>882</output>

<gadget id="calculator">882 - 25</gadget>
<output>857</output>

<result>857</result>