The students went to visit the observatory. There were 3 batches of students visiting in the morning, each batch had 168 students, and there were 246 students visiting in the afternoon. How many students visited this day?
同学们去天文台参观，上午有3批学生去参观，每批有168人，下午参观的学生有246人．这一天一共有多少学生去参观？
<gadget id="calculator">168 * 3</gadget>
<output>504</output>

<gadget id="calculator">504 + 246</gadget>
<output>750</output>

<result>750</result>