To make a wooden box without a cover, the length is 8 decimeters, the width is 5 decimeters, and the height is 4 decimeters. How many square decimeters of planks are used to make such a wooden box?
做一个无盖的木箱，长8分米，宽5分米，高4分米，做这样一个木箱要用木板多少平方分米．
<gadget id="calculator">32 + 20</gadget>
<output>52</output>

<gadget id="calculator">52 * 2</gadget>
<output>104</output>

<gadget id="calculator">40 + 104</gadget>
<output>144</output>

<result>144</result>