A classroom is 6 meters long, 4 meters wide, and 2.5 meters high. Now it is necessary to paint its walls (doors and windows occupy 8 square meters without painting). If paint costs 4 yuan per square meter, how much will it cost to paint this classroom?
一间教室，长6米、宽4米、高2.5米．现在要粉刷它的墙壁(其中门窗占8平方米不刷)．如果每平方米需要花4元涂料，粉刷这个教室需要花费多少元？
<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">6 * 2.5 * 2</gadget>
<output>30</output>

<gadget id="calculator">4 * 2.5 * 2</gadget>
<output>20</output>

<gadget id="calculator">20 - 8</gadget>
<output>12</output>

<gadget id="calculator">24 + 30 + 12</gadget>
<output>66</output>

<gadget id="calculator">66 * 4</gadget>
<output>264</output>

<result>264</result>