Guangming Primary School has an average of 42 students per class and 39 teaching classes. How many students are there in the whole school?
光明小学平均每班有学生42人，有39个教学班，全校有学生多少人？
<gadget id="calculator">42 * 39</gadget>
<output>1_638</output>

<result>1_638</result>