cuboid carton is 0.5 meters long, 0.3 meters wide, and 0.4 meters high. What is the surface area of this cuboid?
一个长方体纸盒长0.5米，宽0.3米，高0.4米，这个长方体的表面积是多少平方米？
<gadget id="calculator">0.5 * 0.3</gadget>
<output>0.15</output>

<gadget id="calculator">0.5 * 0.4</gadget>
<output>0.2</output>

<gadget id="calculator">0.3 * 0.4</gadget>
<output>0.12</output>

<gadget id="calculator">0.15 + 0.2 + 0.12</gadget>
<output>0.47</output>

<gadget id="calculator">0.47 * 2</gadget>
<output>0.94</output>

<result>0.94</result>