The number of adults visiting science and technology museums is twice that of children. If a total of 456 people visit, how many adults are there?
参观科技馆的成人人数是儿童的2倍．如果一共有456人参观，成人有多少人？
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">456 / 3</gadget>
<output>152</output>

<gadget id="calculator">152 * 2</gadget>
<output>304</output>

<result>304</result>