Use hard paper to make a cuboid model with a length of 10 cm, a width of 8 cm, and a height of 4 cm. How much hard paper is needed at least?
用硬纸做一个长为10厘米，宽为8厘米，高为4厘米的长方体模型，至少需要多少硬纸？
<gadget id="calculator">10 * 8</gadget>
<output>80</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">80 + 40 + 32</gadget>
<output>152</output>

<gadget id="calculator">152 * 2</gadget>
<output>304</output>

<result>304</result>