The newly completed teaching building of Xiangyang Primary School has 4 floors, and each floor has 7 classrooms. Each classroom needs to be equipped with 25 sets of double desks and chairs. How many sets of desks and chairs does Xiangyang Primary School need to buy in total?
向阳小学新落成的教学楼有4层，每层有7间教室，每间教室要配25套双人课桌椅，向阳小学一共需要购进课桌椅多少套？
<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<gadget id="calculator">25 * 28</gadget>
<output>700</output>

<result>700</result>