The school carried out afforestation activities. The third grade planted 140 trees, 60 fewer than the fifth grade, and the number of fifth grade plants was exactly four times that of the fourth grade. How many trees were planted in the fourth grade?
学校开展植树造林活动，三年级植了140棵树，比五年级少植60棵，五年级植的棵数正好是四年级4倍，四年级植了多少棵树？
<gadget id="calculator">140 + 60</gadget>
<output>200</output>

<gadget id="calculator">200 / 4</gadget>
<output>50</output>

<result>50</result>