There are 330 seats on and off the stage in the small conference room, and there are 36 rows under the rostrum, with 9 seats in each row. How many seats are there on the rostrum?
小会议室台上台下共有330个座位，主席台下有36排，每排有9个座位，主席台上有多少个座位？
<gadget id="calculator">36 * 9</gadget>
<output>324</output>

<gadget id="calculator">330 - 324</gadget>
<output>6</output>

<result>6</result>