The fourth grade students participated in the tree planting activity. The students from Class 4 and Class 1 were divided into 4 groups, and each group planted 12 trees on average. The students from Class 4 and Class 2 were divided into 3 groups, and each group planted 15 grams on average. How many trees did the two classes plant in total?
四年级同学参加植树活动，四1班同学分为4组，平均每组种了12棵，四2班同学分为3组，平均每组种了15克．两个班一共种了多少棵？
<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<gadget id="calculator">3 * 15</gadget>
<output>45</output>

<gadget id="calculator">48 + 45</gadget>
<output>93</output>

<result>93</result>