To make a cube iron box with a side length of 10 decimeters without a cover, what is the minimum area of the iron sheet?
做一个无盖的棱长为10分米的正方体铁盒，至少要多大面积的铁皮？
<gadget id="calculator">10 * 10 * 5</gadget>
<output>500</output>

<result>500</result>