This spring, students in grades 5 and 6 participated in tree planting activities. A total of 80 trees were planted in the fifth grade, and there were 4 classes in the sixth grade, with an average of 25 trees planted in each class. How many trees were planted in the fifth and sixth grades?
今年春季，五年级和六年级的同学参加植树活动．五年级共植树80棵，六年级有4个班，平均每班植树25棵．五、六年级共植树多少棵？
<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">100 + 80</gadget>
<output>180</output>

<result>180</result>