Find the length or surface area of a cube: the length is 8 decimeters, the width is 2.5 decimeters, and the height is 4 decimeters.
求长或正方体的表面积：长是8分米，宽2.5分米，高4分米．
<gadget id="calculator">8 * 2.5</gadget>
<output>20</output>

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

<gadget id="calculator">2.5 * 4</gadget>
<output>10</output>

<gadget id="calculator">20 + 32 + 10</gadget>
<output>62</output>

<gadget id="calculator">62 * 2</gadget>
<output>124</output>

<result>124</result>