Xiaoyue and Dongdong participated in the tree planting activity organized by the school. The two planted a total of 12 trees, among which Dongdong planted twice as many trees as Xiaoyue. How many trees did Dongdong plant in total?
小悦和冬冬参加学校组织的植树活动．两人一共种了12棵树，其中冬冬植树的棵数是小悦的2倍．冬冬一共种了几棵树？
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<result>8</result>