A cuboid metal water tank without a cover is 5 decimeters long, 4 decimeters wide, and 6 decimeters high. How many square decimeters of iron sheet is needed to make such a water tank? (interface not counted)
一个无盖的长方体铁皮水箱，长5分米，宽4分米，高6分米．做一个这样的水箱至少要铁皮多少平方分米？(接口处不计)
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">4 * 6 * 2</gadget>
<output>48</output>

<gadget id="calculator">5 * 6 * 2</gadget>
<output>60</output>

<gadget id="calculator">20 + 48 + 60</gadget>
<output>128</output>

<result>128</result>