The classroom is 12m long, 8m wide, 3m high, and the door and window area is 30m**2. If the walls and ceiling of the classroom are to be painted, if 0.3kg of paint is used per square meter, how many kilograms of paint are needed in total?
教室长12m，宽8m，高3m，门窗面积30m**2，要粉刷教室的四壁和顶棚，如果每平方米用涂料0.3千克，共需涂料多少千克？
<gadget id="calculator">12 * 8</gadget>
<output>96</output>

<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">8 * 3</gadget>
<output>24</output>

<gadget id="calculator">96 + 36 + 24</gadget>
<output>156</output>

<gadget id="calculator">156 * 2</gadget>
<output>312</output>

<gadget id="calculator">312 - 96 - 30</gadget>
<output>186</output>

<gadget id="calculator">186 * 0.3</gadget>
<output>55.8</output>

<result>55.8</result>