The school participated in the "I Love Anhui, Greening Hefei" activity. There are 4 classes in the fourth grade, and each class is going to plant 25 trees. There are 5 classes in the third grade, and each class is going to plant 12 trees. How many trees are planted in two grades?
学校参加"我爱安徽，绿化合肥"活动，四年级4个班，每班准备植树25棵，三年级5个班，每班准备植树12棵，两个年级共植树多少棵？
<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">12 * 5</gadget>
<output>60</output>

<gadget id="calculator">100 + 60</gadget>
<output>160</output>

<result>160</result>