The number of adults participating in the Science and Technology Museum is three times that of children. If a total of 240 people visit, how many children are there?
参加科技馆的成人人数是儿童的3倍．如果一共有240人参观，儿童有多少人？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">240 / 4</gadget>
<output>60</output>

<result>60</result>