The Xiaoxiao family is going to take a one-day trip to Macau on the weekend. A travel agency quotes: 300 yuan per adult, 180 yuan per child. If Xiaoxiao goes with his father, mother, and grandfather, how much should he pay the travel agency?
笑笑一家准备周末参加澳门一日游．某旅行社报价：大人每位300元，小孩每位180元．如果笑笑和爸爸，妈妈、爷爷一起去，应付给该旅行社多少元？
<gadget id="calculator">300 * 3</gadget>
<output>900</output>

<gadget id="calculator">900 + 180</gadget>
<output>1_080</output>

<result>1_080</result>