A rectangular iron sheet, 25 decimeters long and 20 decimeters wide. Cut off a square with a side length of 5 decimeters from each of the four corners of this rectangular iron sheet, and then fold it into a rectangular iron box. What is the volume of this iron box?
一张长方形铁皮，长25分米，宽20分米．在这张长方形铁皮的四个角上各剪去一个边长是5分米的正方形，然后折成一个长方体铁盒，这个铁盒的体积是多少？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">25 - 10</gadget>
<output>15</output>

<gadget id="calculator">20 - 10</gadget>
<output>10</output>

<gadget id="calculator">15 * 10 * 5</gadget>
<output>750</output>

<result>750</result>