The school organizes a spring outing. Each car can hold 45 people. The first nine cars are all full, and the tenth car still has 20 vacancies. How many people will participate in the spring outing?
学校组织春游，每辆车可以坐45人，前9辆车全部乘满，第10辆车还有20个空位，一共有多少个人参加春游．
<gadget id="calculator">45 * 10</gadget>
<output>450</output>

<gadget id="calculator">450 - 20</gadget>
<output>430</output>

<result>430</result>