The cinema has 680 seats downstairs, and the upstairs seats are four times as many as the downstairs seats. How many seats does this cinema have?
电影院楼下有座位680个，楼上座位是楼下座位的4倍，这个电影院一共有多少个座位？
<gadget id="calculator">680 * 4</gadget>
<output>2_720</output>

<gadget id="calculator">2_720 + 680</gadget>
<output>3_400</output>

<result>3_400</result>