The third and fourth grade students participated in the tree planting activities. The fourth grade planted 1,200 trees, and the third grade planted half of the fourth grade. How many trees were planted in the third and fourth grades?
三、四年级同学参加参加植树活动，四年级植树1200棵，三年级植树的棵数是四年级的一半，三、四年级一共植树多少棵？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1_200 * (1/2)</gadget>
<output>600</output>

<gadget id="calculator">600 + 1_200</gadget>
<output>1_800</output>

<result>1_800</result>