How many square decimeters of iron sheet should be used at least to process 10 uncovered iron sheet water tanks with a ridge length of 3 decimeters?
加工10个棱长3分米的无盖铁皮水箱，至少要用铁皮多少平方分米？
<gadget id="calculator">3 * 3 * 5 * 10</gadget>
<output>450</output>

<result>450</result>