The school carried out flower fragrance campus activities. There are 3 classes in the fourth grade, and each class is going to plant 23 trees. There are 3 classes in the third grade, and each class is going to plant 12 trees. How many trees are planted in two grades?
学校开展花香校园活动，四年级3个班，每班准备植树23棵，三年级3个班，每班准备植树12棵，两个年级共植树多少棵？
<gadget id="calculator">23 * 3</gadget>
<output>69</output>

<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">69 + 36</gadget>
<output>105</output>

<result>105</result>