A classroom is 8 meters long, 6 meters wide, and 4 meters high. To paint the walls and top of the classroom, the area of the classroom is 25 square meters after deducting the doors and windows. 0.4 kg of lime is needed per square meter. How many kilograms of lime will be used to paint this classroom ?
一间教室长8米，宽6米，高4米，要粉刷教室的四壁和顶部，扣除门窗的面积25平方米，每平方米需用0.4千克白灰，粉刷这间教室要用多少千克白灰？
<gadget id="calculator">8 * 6</gadget>
<output>48</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">32 + 24</gadget>
<output>56</output>

<gadget id="calculator">56 * 2</gadget>
<output>112</output>

<gadget id="calculator">112 - 25</gadget>
<output>87</output>

<gadget id="calculator">48 + 87</gadget>
<output>135</output>

<gadget id="calculator">135 * 0.25</gadget>
<output>33.75</output>

<result>33.75</result>