The school organized students to plant trees on Arbor Day. A total of 102 trees were planted in the fourth grade, 12 trees three times less than that in the third grade. How many trees were planted in the third grade? (solution by equation)
植树节学校组织学生植树，四年级一共植了102棵树，比三年级的3倍少12棵，三年级植了多少棵树？(用方程解)
<gadget id="calculator">102 + 12</gadget>
<output>114</output>

<gadget id="calculator">114 / 3</gadget>
<output>38</output>

<result>38</result>