When 3 cubes with edge length of 5dm are assembled into a cuboid, is the surface area of the cuboid increased or decreased compared with the sum of the surface areas of the 3 cubes? How many square decimeters has it increased or decreased?
将3个棱长为5dm的正方体拼成一个长方体，这个长方体表面积与3个正方体表面积之和相比，增加了还是减少了？增加或减少了多少平方分米？
<gadget id="calculator">5 * 5 * 4</gadget>
<output>100</output>

<result>100</result>