Guoqiao Central School has built a new 4-story teaching building with 5 classrooms on each floor. There are 25 desks in each classroom, how many desks are needed in total?
郭桥中心学校新建一栋4层教学楼，每层有5间教室．每间教室放25张桌子，一共需要多少张桌子？
<gadget id="calculator">25 * 5 * 4</gadget>
<output>500</output>

<result>500</result>