Our classroom is 9 meters long, 6 meters wide, and 3 meters high. We need to paint the ceiling and surroundings of the classroom, excluding doors, windows, and blackboards of 12 square meters, and use 400 grams of paint per square meter. How many kilograms of paint are needed in total?
我们的教室长9米，宽6米，高3米，要粉刷教室的顶棚和四周，除去门窗、黑板12㎡，每平方米用涂料400可克，一共要多少千克涂料？
<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<gadget id="calculator">54 + 18 + 27</gadget>
<output>99</output>

<gadget id="calculator">99 * 2</gadget>
<output>198</output>

<gadget id="calculator">198 - 54 - 12</gadget>
<output>132</output>

<gadget id="calculator">132 * 0.4</gadget>
<output>52.8</output>

<result>52.8</result>