cuboid tin bucket without a lid, the bottom is a square with a side length of 3 decimeters, and the height of the bucket is 0.6 meters. How much iron is needed to make a pair of such buckets?
一个无盖的长方体铁皮桶，底面是边长3分米的正方形，桶高是0.6米，做一对这样的水桶至少要多少铁皮？
<gadget id="calculator">0.6 * 10</gadget>
<output>6</output>

<gadget id="calculator">3 * 6 * 4</gadget>
<output>72</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">72 + 9</gadget>
<output>81</output>

<gadget id="calculator">81 * 2</gadget>
<output>162</output>

<result>162</result>