A four-story teaching building has 5 classrooms on each floor. There are a total of 680 desks in this teaching building. How many desks are placed in each classroom on average?
一栋四层的教学楼，每层有5个教室，这栋教学楼里一共放了680张课桌，平均每个教室放多少张课桌？
<gadget id="calculator">580 / 4 / 5</gadget>
<output>29</output>

<result>29</result>