The school has to paint the classrooms. It is known that the length of the classroom is 8 meters, the width is 5 meters, the height is 3 meters, and the area of doors and windows is 10.5 square meters. If the paint fee is 5 yuan per square meter, how much will it cost to paint this classroom?
学校要粉刷教室．已知教室的长8米，宽5米，高3米，门窗面积共10.5平方米．如果每平方米要花5元涂料费，粉刷这个教室需花费多少钱？
<gadget id="calculator">8 * 5</gadget>
<output>40</output>

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

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">24 + 15</gadget>
<output>39</output>

<gadget id="calculator">39 * 2</gadget>
<output>78</output>

<gadget id="calculator">78 - 10.5</gadget>
<output>67.5</output>

<gadget id="calculator">40 + 67.5</gadget>
<output>107.5</output>

<gadget id="calculator">107.5 * 5</gadget>
<output>537.5</output>

<result>537.5</result>