On Arbor Day, Hongxing Primary School planted 180 trees in the third grade, and the number of trees planted in the fourth grade was three times that of the third grade. How many trees were planted in the third and fourth grades of Hongxing Primary School on Arbor Day?
植树节，红星小学三年级植树180棵，四年级植树的棵数是三年级的3倍，植树节红星小学三、四年级一共植树多少棵？
<gadget id="calculator">180 * 3</gadget>
<output>540</output>

<gadget id="calculator">540 + 180</gadget>
<output>720</output>

<result>720</result>