A dustbin is composed of two cubes. The edge length of the small cube is 2 decimeters, the edge length of the big cube is 5 decimeters, and the top of the small cube is open for people to throw garbage. How many square decimeters of iron sheet is needed to make such a dustbin? (Hint: to subtract three 3*2 areas)
一种垃圾箱是由大小两个正方体组成的．其中小正方体的棱长是2分米，大正方体的棱长是5分米，小正方体的顶部敞开，便于人们扔垃圾．做一个这样的垃圾箱，至少需要多少平方分米的铁皮？(提示：要减去3个3*2的面积)
<gadget id="calculator">2 * 2 * 4</gadget>
<output>16</output>

<gadget id="calculator">5 * 5 * 6</gadget>
<output>150</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">150 - 4</gadget>
<output>146</output>

<gadget id="calculator">16 + 146</gadget>
<output>162</output>

<result>162</result>