Guangming Xiaoyang participated in the tree planting activity. The fourth grade planted 120 trees, and the third grade planted 7 trees less than half of the fourth grade. How many trees were planted in the third grade?
光明小阳参加植树活动，四年级植树120棵，三年级植的比四年级的一半少7棵，三年级植树多少棵？
<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">60 - 7</gadget>
<output>53</output>

<result>53</result>